LP87702KRHBR_技术文档

LP87702

SNVSBU3 – MARCH 2021

LP87702 Dual Buck Converter and 5-V Boost With Diagnostic Functions

•

Factory Automation:

1 Features

– Industrial Robot – Safety Area Scanner

– Autonomous Guided Vehicle (AGV)

– Level Transmitter – Sensing

Industrial Transport:

•

FMEDA and Functional Safety Manual Available

to Support System-Level Functional Safety

Requirements up to SIL-2 (IEC 61508)

Two High-Efficiency Step-Down DC/DC

converters:

•

– Traffic Enforcement

– Intersection Monitoring

– Road-Railway Sensors

– Intelligent Lighting Sensors

Appliances:

– AC Control

– Appliances User Interface and Connectivity

Modules

– Maximum Output Current 3.5 A

– 2-MHz, 3-MHz, or 4-MHz Switching Frequency

– Auto PWM/PFM and Forced-PWM Operations

– Output Voltage = 0.7 V to 3.36 V

5-V 600 mA Boost Converter

Two Inputs for External Voltage Monitoring

Two Programmable Power-Good Signals

Dedicated Reference Voltage for Diagnostics

Window Watchdog with Reset Output

External Clock Input to Synchronize Switching

Spread-Spectrum Modulation

•

3 Description

The LP87702 contains two step-down DC/DC

converters, and a 5-V boost converter to support

safety critical applications. The device integrates two

voltage monitoring inputs for external power supplies

and a window watchdog.

Programmable Start-up and Shutdown Delays and

Sequencing with Enable Signal

•

Configurable General Purpose Outputs (GPOs)

I²C-Compatible Interface

The automatic PWM/PFM (AUTO mode) operation

gives high efficiency over a wide output current range

for buck converters.

Interrupt Function with Programmable Masking

Output Short-Circuit and Overload Protection

Overtemperature Warning and Protection

Overvoltage Protection (OVP) and Undervoltage

Lockout (UVLO)

This device contains one-time-programmable (OTP)

memory. Each orderable part number has specific

OTP settings for a given application. Details of the

default OTP configuration for each orderable part

number is found in the technical reference manual.

2 Applications

Device Information⁽¹⁾

•

Building Automation:

PART NUMBER

LP87702

PACKAGE

BODY SIZE (NOM)

– Automated Doors and Gates

– Motion Detector (PIR/Motion Sensor)

– Video Surveillance:

VQFN (32)

5.00 mm × 5.00 mm

(1) See the orderable addendum at the end of the data sheet for

all available packages.

•

Occupancy Detection (People Tracking,

People Counting)

100

90

VIN

VOUT0

VIN_B0

VIN_B1

VANA

SW_B0

FB_B0

LOAD

SW_BST

VOUT1

SW_B1

FB_B1

LOAD

80

NRST

SDA (EN3)

SCL (EN2)

nINT

70

VOUT2

EN1

VOUT_BST

LOAD

CLKIN (GPO2/WD_DIS)

60

PG0

PG1 (GPO1)

GPO0

VIN=3.3V, VOUT=1.2V

VIN=3.3V, VOUT=1.8V

VIN=3.3V, VOUT=2.3V

VMON1

VMON2

WDI

WD_RESET

50

GNDs

1

10

100

Output Current (mA)

1000 5000

Exce

Buck Efficiency vs Output Current

Simplified Schematic

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.

LP87702

SNVSBU3 – MARCH 2021

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Table of Contents

1 Features............................................................................1

2 Applications.....................................................................1

3 Description.......................................................................1

4 Revision History.............................................................. 2

5 Pin Configuration and Functions...................................3

6 Specifications.................................................................. 5

6.1 Absolute Maximum Ratings........................................ 5

6.2 ESD Ratings............................................................... 5

6.3 Recommended Operating Conditions.........................5

6.4 Thermal Information....................................................6

6.5 Electrical Characteristics.............................................6

6.6 I²C Serial Bus Timing Parameters............................ 12

6.7 Typical Characteristics..............................................14

7 Detailed Description......................................................15

7.1 Overview...................................................................15

7.2 Functional Block Diagram.........................................16

7.3 Feature Descriptions.................................................16

7.4 Device Functional Modes..........................................39

7.5 Programming............................................................ 41

7.6 Register Maps...........................................................44

8 Application and Implementation..................................78

8.1 Application Information............................................. 78

8.2 Typical Application.................................................... 78

9 Power Supply Recommendations................................87

10 Layout...........................................................................87

10.1 Layout Guidelines................................................... 87

10.2 Layout Example...................................................... 88

11 Device and Documentation Support..........................89

11.1 Third-Party Products Disclaimer............................. 89

11.2 Receiving Notification of Documentation Updates..89

11.3 Support Resources................................................. 89

11.5 Electrostatic Discharge Caution..............................89

11.6 Glossary..................................................................89

12 Mechanical, Packaging, and Orderable

Information.................................................................... 89

4 Revision History

NOTE: Page numbers for previous revisions may differ from page numbers in the current version.

DATE

REVISION

NOTES

March 2021

*

Initial Release

2

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5 Pin Configuration and Functions

24

23

22

21

20

19

18

17

SW_B0

VIN_B0

PG0

SW_B1

25

26

27

28

29

30

31

32

16

15

14

13

12

11

10

9

VIN_B1

THERMAL PAD

GPO0

VMON1

VMON2

PG1 (GPO1)

NRST

PGND_BST

SW_BST

1

2

3

4

5

6

7

8

Figure 5-1. RHB Package 32-Pin VQFN With Thermal Pad Top View

Table 5-1. Pin Functions

TYPE

DESCRIPTION

NAME

AGND

CLKIN

EN1

NUMBER

4

22

19

2

G

Ground

D/I/O External clock input. Alternative function is general purpose digital output 2 (GPO2).

D/I

A

Programmable Enable 1 signal.

FB_B0

FB_B1

GPO0

nINT

Output voltage feedback for Buck0.

Output voltage feedback for Buck1.

General purpose digital output 0.

Open-drain interrupt output. Active LOW.

Reset signal for the device.

3

A

12

1

D/O

D/I

D/O

NRST

PG0

11

29

Programmable power-good indication signal.

Programmable power-good indication signal. Alternative function is general purpose digital output

1 (GPO1).

PG1

32

D/O

PGND_B0

PGND_B1

PGND_BST

23, 24

17, 18

10

P/G

Power ground for Buck0.

Power Ground for Buck1.

Power ground for boost.

Serial interface clock input for I2C access. Connect a pullup resistor. Alternative function is

programmable to the enable 2 signal.

SCL

SDA

20

21

D/I

Serial interface data input and output for I2C access. Connect a pullup resistor. Alternative

function is programmable to the enable 3 signal.

D/I/O

SW_B0

SW_B1

SW_BST

VANA

25, 26

P/O

P/I

P

Buck0 switch node.

15, 16

Buck1 switch node.

9

5

Boost input.

Supply voltage for analog and digital blocks. Must be connected to same node with VIN_Bx.

Voltage monitoring input 1.

VMON1

30

A/I

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Table 5-1. Pin Functions (continued)

TYPE

DESCRIPTION

NAME

NUMBER

VMON2

31

A/I

P/I

Voltage monitoring input 2.

Input for Buck0. The separate power pins VIN_Bx are not connected together internally – VIN_Bx

pins must be connected together in the application and be locally bypassed.

VIN_B0

VIN_B1

27, 28

Input for Buck1. The separate power pins VIN_Bx are not connected together internally – VIN_Bx

pins must be connected together in the application and be locally bypassed.

13, 14

P/I

VOUT_BST

WD_RESET

WDI

8

6

P/O

D/O

D/I

G

Boost output.

Reset output from window watchdog

Digital input signal for window watchdog

7

Thermal pad

N/A

A: Analog Pin, D: Digital Pin, G: Ground Pin, P: Power Pin, I: Input Pin, O: Output Pin

4

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6 Specifications

6.1 Absolute Maximum Ratings

Over operating free-air temperature range (unless otherwise noted)^{(1) (2)}

MIN

MAX

UNIT

VIN_B0,

Voltage on input power connections

–0.3

6

VIN_B1, SW_BST,

VANA

V

SW_B0, SW_B1

FB_B0, FB_B1

VOUT_BST

Voltage on buck switch nodes

Voltage on buck voltage sense nodes

Voltage on boost output

–0.3

(VIN_Bx + 0.3 V) with

6-V maximum

V

(VANA + 0.3 V) with

6-V maximum

V

–0.3

6

SCL (EN2), SDA (EN3), Voltage on voltage monitoring pins

VMON1, VMON2

(VANA + 0.3 V) with

6-V maximum

NRST, EN1, nINT

Voltage on logic pins (input or output pins)

–0.3

6

PG0, PG1 (GPO1),

GPO0, CLKIN (GPO2),

WDI, WD_RESET

(VANA + 0.3 V) with

6-V maximum

V

T_J-MAX

T_stg

Junction temperature

Storage temperature

−40

–65

150

260

°C

Maximum lead temperature (soldering, 10 sec.)

(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress

ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under

Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device

reliability.

(2) All voltage values are with respect to network ground.

6.2 ESD Ratings

VALUE

±2000

±500

UNIT

Human-body model (HBM), per AEC Q100-002⁽¹⁾

All pins

V_(ESD)

Electrostatic discharge

V

Charged-device model (CDM), per AEC

Corner pins (1, 8, 9, 16, 17,

24, 25, 32)

Q100-011

±750

(1) AEC Q100-002 indicates that HBM stressing shall be in accordance with the ANSI/ESDA/JEDEC JS-001 specification.

6.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)

MIN

MAX

UNIT

INPUT VOLTAGE

VIN_B0, VIN_B1, SW_BST, VANA

VMON1, VMON2

Voltage on input power connections

Voltage on voltage monitoring pins

Voltage on logic pins (input or output pins)

2.8

0

5.5

V

NRST, EN1, EN2, EN3, nINT

0

PG0, PG1 (GPO1), GPO0, CLKIN

(GPO2), WDI, WD_RESET

Voltage on logic pins (input or output pins)

0

VANA

1.95

V

Voltage on I2C interface, Standard (100 kHz), Fast

(400 kHz), Fast+ (1 MHz), and High-Speed (3.4

MHz) Modes

0

SCL, SDA

Voltage on I2C interface, Standard (100 kHz), Fast

(400 kHz), and Fast+ (1 MHz) Modes

VANA with 3.6-V

maximum

TEMPERATURE

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over operating free-air temperature range (unless otherwise noted)

MIN

−40

MAX

140

UNIT

°C

Junction temperature, T_J

Ambient temperature, T_A

125

°C

6.4 Thermal Information

RHB (VQFN)

THERMAL METRIC⁽¹⁾

UNIT

32 PINS

31.7

17.1

5.6

R_θJA

Junction-to-ambient thermal resistance

Junction-to-case (top) thermal resistance

Junction-to-board thermal resistance

°C/W

R_θJCtop

R_θJB

ψ_JT

Junction-to-top characterization parameter

Junction-to-board characterization parameter

Junction-to-case (bottom) thermal resistance

0.2

ψ_JB

5.6

R_θJCbot

1.1

(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application

report.

6.5 Electrical Characteristics

Limits apply over the junction temperature range –40°C ≤ T_J≤ 140°C, specified V_VANA, V_{VIN_Bx}, V_{VOUT_Bx}, V_{VOUT_BST}, and

I_OUTrange, unless otherwise noted. Typical values are at T_A= 25°C, V_VANA= V_{VIN_Bx}= 3.3 V, V_{OUT_BST}= 5 V and V_{OUT_Bx}

=

1 V, unless otherwise noted. ^{(1) (2)}

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX UNIT

EXTERNAL COMPONENTS

Input filtering capacitance Effective capacitance, connected from

C_{IN_BUCK}

1.9

15

10

22

µF

for buck converters

VIN_Bx to PGND_Bx

Output filtering

capacitance for buck

converters

C_{OUT_BUC}

Effective total capacitance. Maximum

includes POL capacitance

100

µF

K

Point-of-load (POL)

capacitance for buck

converters

C_{OUT_BUC}

Optional POL capacitance

Effective capacitance

22

K_POL

Output filtering

C_{OUT_BST}capacitance for boost

converter

10

40

10

Input and output

ESR_C

[1-10] MHz

2

mΩ

µH

capacitor ESR

0.47

Inductor for buck

L_BUCK

Inductance of the inductor

converters

–30%

30%

Inductance of the inductor, 2-MHz switching

Inductance of the inductor, 4-MHz switching

Inductance of the inductor

1

Inductor for boost

converters

L_BST

µH

DCR_L

BUCK CONVERTERS

V_{(VIN_Bx)}

V_(VANA)

Inductor DCR

25

mΩ

,

Input voltage range

2.8

0.7

3.3

5.5

V

Programmable voltage range

Step size, 0.7 V ≤ V_OUT< 0.73 V

Step size, 0.73 V ≤ V_OUT< 1.4 V

Step size, 1.4 V ≤ V_OUT≤ 3.36 V

Output current

1

10

5

3.36

V_{OUT_Bx}Output voltage

mV

A

20

I_{OUT_Bx}

Output current

3.5 ⁽³⁾

6

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Limits apply over the junction temperature range –40°C ≤ T_J≤ 140°C, specified V_VANA, V_{VIN_Bx}, V_{VOUT_Bx}, V_{VOUT_BST}, and

I_OUTrange, unless otherwise noted. Typical values are at T_A= 25°C, V_VANA= V_{VIN_Bx}= 3.3 V, V_{OUT_BST}= 5 V and V_{OUT_Bx}

1 V, unless otherwise noted. ^{(1) (2)}

=

PARAMETER

TEST CONDITIONS

V_{(VIN_Bx)}– V_OUT,I_{OUT_Bx}≤ 2 A

V_{(VIN_Bx)}– V_OUT,I_{OUT_Bx}> 2 A

MIN

0.8

1

TYP

MAX UNIT

Minimum voltage

difference between

V_{(VIN_Bx)}and V_{OUT_Bx}for

electrical characteristics

V

DC output voltage

accuracy, includes

voltage reference, DC

load and line regulations,

process and temperature

Force PWM mode, V_OUT˂ 1.0 V

Force PWM mode, V_OUT≥ 1.0 V

–20

–2%

–20

20

2%

40

mV

PFM mode, V_OUT˂ 1.0 V, the average output

voltage level is increased by max. 20 mV

PFM mode, V_OUT≥ 1.0 V, the average output

voltage level is increased by max. 20 mV

–2%

2% + 20mV

PWM mode, V_OUT= 1.2 V, f_SW= 4 MHz,

C_OUT= 22 + 22 µF (GCM31CR71A226KE02)

5

Ripple voltage

mV_p-p

%/V

PFM mode, L = 0.47 µH, C_OUT= 22 + 22 µF

(GCM31CR71A226KE02)

25

±0.05

0.3%

DC_LNR

DC_LDR

DC line regulation

I_OUT= I_OUT(max)

DC load regulation in

PWM mode

V_{OUT_Bx}= 1.0 V, I_OUTfrom 0 to I_OUT(max)

I_OUT= 0 A to 3 A, T_R= T_F= 1 µs, PWM

mode, V_{VIN_Bx}= 3.3V, V_{OUT_Bx}= 1.2 V, C_OUT

= 22 + 22 µF, L = 0.47 µH, f_SW= 4 MHz

Transient load step

response

T_LDSR

±65

±20

mV

V_{(VIN_Bx)}stepping 3 V ↔ 3.5 V, T_R= T_F= 10

µs, I_OUT= I_OUT(max)

T_LNSR

Transient line response

Programmable range

1.5

4.5

Forward current limit for

both bucks (peak for

every switching cycle)

Step size

0.5

7.5%

2

I_{LIM FWD}

A

Accuracy, V_{(VIN_Bx)}≥ 3 V, I_LIM= 4 A

Accuracy, 2.8 V ≤ V_{(VIN_Bx)}< 3 V, I_LIM= 4 A

–5%

–20%

1.6

20%

3

I_{LIM NEG}

R_DS(ON)

Negative current limit

A

On-resistance, high-side Each phase, between VIN_Bx and SW_Bx

FET

60

55

110

mΩ

BUCK HS

FET

pins (I = 1.0 A)

R_DS(ON)

On-resistance, low-side

FET

Each phase, between SW_Bx and PGND_Bx

pins (I = 1.0 A)

80

mΩ

BUCK LS

FET

2-MHz setting or V_{OUT_Bx}< 0.8 V

3-MHz setting and V_{OUT_Bx}≥ 0.8 V

4-MHz setting and V_{OUT_Bx}≥ 1.1 V

1.8

2.7

3.6

2

3

4

2.2

Switching frequency,

PWM mode

OTP programmable

ƒ_SW

3.3 MHz

4.4

From ENx to V_{OUT_Bx}= 0.35 V (slew-rate

control begins)

Start-up time (soft start)

Overshoot during start-up

120

µs

50

mV

Output voltage slew-

rate⁽⁴⁾

SLEW_RATEx[2:0] = 010, V_{VOUT_Bx}≥ 0.7 V

SLEW_RATEx[2:0] = 011, V_{VOUT_Bx}≥ 0.7 V

SLEW_RATEx[2:0] = 100, V_{VOUT_Bx}≥ 0.7 V

SLEW_RATEx[2:0] = 101, V_{VOUT_Bx}≥ 0.7 V

SLEW_RATEx[2:0] = 110, V_{VOUT_Bx}≥ 0.7 V

SLEW_RATEx[2:0] = 111, V_{VOUT_Bx}≥ 0.7 V

–15%

10

7.5

15% mV/µs

Output voltage slew-

rate⁽⁴⁾

Output voltage slew-

rate⁽⁴⁾

3.8

Output voltage slew-

rate⁽⁴⁾

1.9

Output voltage slew-

rate⁽⁴⁾

0.94

0.47

Output voltage slew-

rate⁽⁴⁾

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Limits apply over the junction temperature range –40°C ≤ T_J≤ 140°C, specified V_VANA, V_{VIN_Bx}, V_{VOUT_Bx}, V_{VOUT_BST}, and

I_OUTrange, unless otherwise noted. Typical values are at T_A= 25°C, V_VANA= V_{VIN_Bx}= 3.3 V, V_{OUT_BST}= 5 V and V_{OUT_Bx}

1 V, unless otherwise noted. ^{(1) (2)}

=

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX UNIT

PFM-to-PWM switch -

current threshold⁽⁵⁾

I_PFM-PWM

I_PWM-PFM

520

mA

Ω

PWM-to-PFM switch -

current threshold⁽⁵⁾

240

125

Output pull-down

resistance

Converter disabled

75

175

BOOST CONVERTER

Input voltage range for

2.8

4.5

3.3

4

V

boost power inputs

V_{IN_BST}

Input voltage range when

bypass switch mode

selected

5.5

BOOST_VSET = 00

4.9

5.0

5.1

5.2

BOOST_VSET = 01

Output voltage, boost

mode

V_{OUT_BST}

V

BOOST_VSET = 10

BOOST_VSET = 11

I_{OUT_BST}Output current

Both boost and bypass mode

BOOST_ILIM = 00, V_{IN_BST}< 3.6 V

BOOST_ILIM = 01, V_{IN_BST}< 3.6 V

BOOST_ILIM = 10, V_{IN_BST}< 3.6 V

BOOST_ILIM = 11, V_{IN_BST}< 3.6 V

0.6

1.3

1.9

2.3

3.4

A

I_{LIM_BST}

Output current limit

0.8

1.1

1.5

2.2

1

1.4

1.9

2.8

DC output voltage

accuracy, includes

V_{OUT_BST}voltage reference, DC

Default output voltage

Iout = 250 mA

–3%

3%

83

load and line regulations,

_DC

process and temperature.

Boost mode

V_DROP

Voltage drop, bypass

mode,

mV

Ripple voltage, boost

mode

22 µF effective output capacitance

I_OUT= 1 mA to I_OUT(max)

20

mV_p-p

DC load regulation, boost

mode

DC_LDR

T_LDSR

0.3%

Transient load step

response, boost mode

I_OUT= 1 mA to 250 mA, T_R= T_F= 1 µs, 22

µF effective output capacitance, VIN > 3 V

–220

220

mV

mA

During start-up, both boost and bypass

mode. Short circuit current limit applies until

V_{OUT_BST}= V_{IN_BST}

Short circuit current

limitation

I_SHORT

625

R_DS(ON)

On-resistance, high-side Pin-to-pin, between SW_BST and

145

90

220

175

mΩ

FET

VOUT_BST pins (I = 250 mA)

BST HS FET

R_DS(ON)

On-resistance, low-side

FET

Pin-to-pin, between SW_BST and

PGND_BST pins (I = 250 mA)

BST LS FET

2-MHz setting

4-MHz setting

1.8

3.6

2

4

2.2 MHz

4.4 MHz

Switching frequency,

boost mode

ƒ_SW

From enable to boost VOUT within 3% of

target value. C_{OUT_BST}= 22 µF

Start-up time, boost mode

450

135

µs

Ω

Output pull-down

resistance

Converter disabled

EXTERNAL CLOCK AND PLL

8

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Limits apply over the junction temperature range –40°C ≤ T_J≤ 140°C, specified V_VANA, V_{VIN_Bx}, V_{VOUT_Bx}, V_{VOUT_BST}, and

I_OUTrange, unless otherwise noted. Typical values are at T_A= 25°C, V_VANA= V_{VIN_Bx}= 3.3 V, V_{OUT_BST}= 5 V and V_{OUT_Bx}

1 V, unless otherwise noted. ^{(1) (2)}

=

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX UNIT

Nominal frequency

1

24

MHz

µs

External input clock⁽⁶⁾

Nominal frequency step size

1

Required accuracy from nominal frequency

–30%

10%

1.8

Delay for detecting loss of external clock,

nominal internal clock, clock accuracy ±10%

External clock detection

Delay for detecting valid external clock,

nominal internal clock, clock accuracy ±10%

20

Clock change delay

(internal to external)

Delay from valid clock detection to use of

external clock

600

300

µs

PLL output clock jitter

Cycle to cycle

ps, p-p

MONITORING FUNCTIONS

Voltage threshold, VANA_THRESHOLD = 0

Voltage threshold, VANA_THRESHOLD = 1

3.3

5.0

V

VANA Voltage Monitoring Voltage window, VANA_WINDOW = 00

Voltage window, VANA_WINDOW = 01

Voltage window, VANA_WINDOW = 10 or 11

VMONx_THRESHOLD = 000

±3%

±4%

±9%

±4%

±5%

±10%

0.65

0.8

±5%

±6%

±11%

VMONx_THRESHOLD = 001

VMONx_THRESHOLD = 010

1.0

VMON1 and VMON2

Voltage Monitoring

VMONx_THRESHOLD = 100

Thresholds

VMONx_THRESHOLD = 011

1.1

V

1.2

VMONx_THRESHOLD = 101

VMONx_THRESHOLD = 110

VMONx_THRESHOLD = 111

1.3

1.8

VMONx_WINDOW = 00,

VMONx_THRESHOLD from 000 to 111

±1%

±2%

±3%

±2%

±3%

±4%

±5%

VMONx_WINDOW = 01,

VMONx_THRESHOLD from 000 to 111

±3%

±4%

VMON1 and VMON2

Voltage Monitoring

VMONx_WINDOW = 10,

Windows

VMONx_THRESHOLD from 000 to 111

VMONx_WINDOW = 11,

VMONx_THRESHOLD from 000 to 111

±5%

±6%

±7%

BUCKx_WINDOW = 00

±20

±37

±30

±50

±40

±63

BUCKx_WINDOW = 01

BUCKx_WINDOW = 10

BUCKx_WINDOW = 11

BOOST_WINDOW = 00

BOOST_WINDOW = 01

BOOST_WINDOW = 10

BOOST_WINDOW = 11

VANA, VMONx and BOOST monitoring

BUCKx monitoring

Buck0 and Buck1 Voltage

Monitoring Windows

mV

±57

±70

±83

±77

±90

±103

±3.4%

±5.4%

±7.4%

±9.4%

17

±0.6%

±2.6%

±4.6%

±6.6%

12

±2%

±4%

±6%

±8%

Boost Voltage Monitoring

Deglitch time

μs

°C

6

9

PROTECTION FUNCTIONS

Temperature rising, TDIE_WARN_LEVEL = 0

Temperature rising, TDIE_WARN_LEVEL = 1

Hysteresis

115

130

125

140

20

135

150

Thermal warning

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Limits apply over the junction temperature range –40°C ≤ T_J≤ 140°C, specified V_VANA, V_{VIN_Bx}, V_{VOUT_Bx}, V_{VOUT_BST}, and

I_OUTrange, unless otherwise noted. Typical values are at T_A= 25°C, V_VANA= V_{VIN_Bx}= 3.3 V, V_{OUT_BST}= 5 V and V_{OUT_Bx}

1 V, unless otherwise noted. ^{(1) (2)}

=

PARAMETER

TEST CONDITIONS

MIN

TYP

150

20

MAX UNIT

Temperature rising

140

160

Thermal shutdown

°C

V

Hysteresis

Voltage rising, VANA_OVP_SEL = 0

Voltage falling, VANA_OVP_SEL = 0

Voltage rising, VANA_OVP_SEL = 1

Voltage falling, VANA_OVP_SEL = 1

Hysteresis

5.6

5.45

4.1

5.8

6.1

5.96

4.6

5.73

4.3

VANA_OVPVANA Overvoltage

VANA_UVLVANA Undervoltage

3.95

40

4.23

4.46

200

2.75

2.7

mV

V

Voltage rising

2.51

2.5

2.63

2.6

Lockout

O

Voltage falling

BUCKx short circuit

detection

Threshold

0.32

0.35

0.45

V

Bypass short circuit

current limit

270

420

mA

LOAD CURRENT MEASUREMENT FOR BUCK CONVERTERS

Current corresponding to maximum output

code (note: maximum current for LP87702

buck is 3.5A)

Current measurement

range

10.22

A

Resolution

LSB

20

mA

Measurement accuracy

I_OUT> 1A

<10%

Auto mode (automatically changing to PWM

mode for the measurement)

50

Measurement time

µs

PWM mode

25

CURRENT CONSUMPTION

Shutdown current

consumption

NRST = 0

1

9

µA

Standby current

consumption, converters NRST = 1

disabled

Active current

consumption, one buck

converter enabled in

Auto mode, internal RC

oscillator

I_{OUT_Bx}= 0 mA, not switching

55

90

µA

Active current

consumption, two buck

converters enabled in

Auto mode, internal RC

oscillator

I_{OUT_Bx}= 0 mA, not switching

Active current

consumption during PWM

operation, one buck

converter enabled

I_{OUT_Bx}= 0 mA

15

27

mA

Active current

consumption during PWM

operation, two buck

converters enabled

I_{OUT_Bx}= 0 mA

Active current

consumption, Boost

converter in PWM

operation

I_{OUT_BST}= 0 mA, f_SW= 4 MHz

18

2

mA

PLL and clock detector

current consumption

Additional current consumption when

enabled, 2 MHz external clock

10

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Limits apply over the junction temperature range –40°C ≤ T_J≤ 140°C, specified V_VANA, V_{VIN_Bx}, V_{VOUT_Bx}, V_{VOUT_BST}, and

I_OUTrange, unless otherwise noted. Typical values are at T_A= 25°C, V_VANA= V_{VIN_Bx}= 3.3 V, V_{OUT_BST}= 5 V and V_{OUT_Bx}

1 V, unless otherwise noted. ^{(1) (2)}

=

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX UNIT

DIGITAL INPUT SIGNALS SCL, SDA, NRST, EN1, EN2, EN3, CLKIN,

WDI

V_IL

V_IH

Input low level

Input high level

0.4

V

1.2

10

Hysteresis of Schmitt

Trigger inputs

V_HYS

80

500

200

mV

kΩ

ENx, CLKIN, WDI pull-

down resistance

ENx_PD = 1, CLKIN_PD = 1, WDI_PD = 1

Always enabled

NRST pull-down

resistance

DIGITAL OUTPUT SIGNALS nINT, SDA

SDA: I_SOURCE= 20 mA

nINT: I_SOURCE= 2 mA

0.5

0.4

V_OL

R_P

Output low level

V

External pull-up resistor

for nINT

To VIO Supply

10

kΩ

DIGITAL OUTPUT SIGNALS PGOOD, PG1, GPO0, GPO1, GPO2,

WD_RESET

V_OL

V_OH

Output low level

I_SOURCE= 2 mA

I_SINK= 2 mA

0.4

Output high level,

configured to push-pull

V_VANA- 0.4

V_VANA

V

Supply voltage for

V_PU

external pull-up resistor,

configured to open-drain

V_VANA

External pull-up resistor,

configured to open-drain

R_PU

10

kΩ

ALL DIGITAL INPUTS

All logic inputs except NRST, over pin voltage

range, when PD not enabled

−1

–1

1

µA

I_LEAK

Input current

NRST, over pin voltage range. Other logic

inputs when PD enabled.

20

(1) All voltage values are with respect to network ground.

(2) Minimum (MIN) and Maximum (MAX) limits are specified by design, test, or statistical analysis.

(3) The maximum output current can be limited by the forward current limit I_{LIM FWD}. The maximum output current is also limited by

the junction temperature and maximum average current over lifetime. The power dissipation inside the die increases the junction

temperature and limits the maximum current depending of the length of the current pulse, efficiency, board and ambient temperature.

(4) The slew-rate can be limited by the current limit (forward or negative current limit), output capacitance and load current. Applies when

internal oscillator is used.

(5) The final PFM-to-PWM and PWM-to-PFM switchover current varies slightly and is dependant on the output voltage, input voltage and

the inductor current level.

(6) The external clock frequency must be selected so that buck switching frequency is above 1.7 MHz.

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6.6 I²C Serial Bus Timing Parameters

See ⁽¹⁾

.

MIN

MAX

100

400

1

UNIT

Standard mode

kHz

Fast mode

f_SCL

Serial clock frequency

Fast mode +

High-speed mode, C_b= 100 pF

High-speed mode, C_b= 400 pF

Standard mode

3.4

1.7

MHz

4.7

1.3

0.5

160

320

4

Fast mode

µs

ns

µs

ns

t_LOW

SCL low time

Fast mode +

High-speed mode, C_b= 100 pF

High-speed mode, C_b= 400 pF

Standard mode

Fast mode

0.6

0.26

60

t_HIGH

SCL high time

Data setup time

Data hold time

Fast mode +

High-speed mode, C_b= 100 pF

High-speed mode, C_b= 400 pF

Standard mode

120

250

100

50

Fast mode

t_SU;DAT

t_HD;DAT

t_SU;STA

ns

Fast mode +

High-speed mode

Standard mode

10

0.01

10

3.45

0.9

Fast mode

µs

ns

Fast mode +

High-speed mode, C_b= 100 pF

High-speed mode, C_b= 400 pF

Standard mode

70

10

150

4.7

0.6

0.26

160

4

Fast mode

µs

ns

µs

ns

µs

Setup time for a start or a

repeated start condition

Fast mode +

High-speed mode

Standard mode

Fast mode

0.6

0.26

160

4.7

1.3

0.5

4

Hold time for a start or a

repeated start condition

t_HD;STA

Fast mode +

High-speed mode

Standard Mode

Bus free time between a stop

and start condition

t_BUF

Fast Mode

Fast mode +

Standard Mode

Fast Mode

0.6

0.26

160

µs

ns

t_SU;STO

Setup time for a stop condition

Fast mode +

High-speed mode

Standard mode

1000

300

120

80

Fast mode

20+0.1 C_b

t_rDA

Rise time of SDA signal

Fast mode +

ns

High-speed mode, C_b= 100 pF

High-speed mode, C_b= 400 pF

10

20

160

12

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See ⁽¹⁾

.

MIN

MAX

250

120

80

UNIT

Standard mode

Fast mode

20+0.1 C_b

10

t_fDA

Fall time of SDA signal

Fast mode +

ns

High-speed mode, C_b= 100 pF

High-speed mode, C_b= 400 pF

Standard mode

20

160

1000

300

120

40

Fast mode

20+0.1 C_b

t_rCL

t_rCL1

t_fCL

Rise time of SCL signal

Fast mode +

ns

High-speed mode, C_b= 100 pF

High-speed mode, C_b= 400 pF

Standard mode

10

20

80

1000

300

120

80

Fast mode

20+0.1 C_b

Rise time of SCL signal after

a repeated start condition and

after an acknowledge bit

Fast mode +

High-speed mode, C_b= 100 pF

High-speed mode, C_b= 400 pF

Standard mode

10

20

160

300

120

40

Fast mode

20+0.1 C_b

10

Fall time of a SCL signal

Fast mode +

High-speed mode, C_b= 100 pF

High-speed mode, C_b= 400 pF

20

80

Capacitive load for each bus

line (SCL and SDA)

C_b

400

50

pF

ns

Pulse width of spike

suppressed (Spikes shorter

than indicated width are

suppressed)

Fast mode, Fast mode +

High-speed mode

t_SP

10

(1) C_brefers to the capacitance of one bus line. C_bis expressed in pF units.

t_BUF

SDA

t_HD;STA

t_rCL

t_fDA

t_rDA

t_SP

t_LOW

t_fCL

SCL

t_HD;STA

t_SU;STA

t_SU;STO

t_HIGH

t_HD;DAT

S

t_SU;DAT

S

RS

P

START

REPEATED

START

STOP

START

Figure 6-1. I²C Timing

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6.7 Typical Characteristics

Unless otherwise specified: V_IN= 3.3 V, T_A= 25°C, ƒ_SW-setting 4 MHz, L0 = L1 = 0.47 µH (TOKO

DFE252012PD-R47M), L2 = 1 µH (TFM252012ALMA1R0), C_{OUT_BUCK}= 22 µF, and C_{POL_BUCK}= 22 µF,

C_{OUT_BOOST}= 22 µF. Measurements are done using connections in the Figure 8-1.

4

3.5

3

30

25

20

15

10

5

2.5

2

1.5

1

0.5

0

2.8

3.1

3.4

3.7

4 4.3

Input Voltage (V)

4.6

4.9

5.2

5.5

2.8

3.1

3.4

3.7

4

4.3

Input Voltage (V)

Regulators disabled

4.6

4.9

5.2

5.5

D016

D015

V_(NRST)= 0 V

V_(NRST)= 1.8 V

Figure 6-2. Shutdown Current Consumption vs

Input Voltage

Figure 6-3. Standby Current Consumption vs Input

Voltage

90

85

80

75

70

65

60

55

50

45

40

50

45

40

35

30

25

20

15

10

5

0

2.8

3.1

3.4

3.7

4

4.3

Input Voltage (V)

Load = 0 mA

4.6

4.9

5.2

5.5

2.8

3.1

3.4

3.7

4

4.3

Input Voltage (V)

Load = 0 mA

4.6

4.9

5.2

5.5

D013

D012

V_OUT= 1.2 V

Figure 6-4. Active State Current Consumption vs

Input Voltage, One Buck Converter Enabled in PFM

Mode

Figure 6-5. Active State Current Consumption vs

Input Voltage, One Buck Converter Enabled in

PWM Mode

50

45

40

35

30

25

20

15

10

5

0

2.8

3

3.2

3.4

Input Voltage (V)

Load = 0 mA

3.6

3.8

4

D014

V_OUT= 5.0 V

Figure 6-6. Active State Current Consumption vs Input Voltage, Boost Converter Enabled in PWM Mode

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7 Detailed Description

7.1 Overview

The LP87702 is a high-efficiency, high-performance power supply IC with two step-down DC/DC converters

(Buck0 and Buck1) and boost converter for automotive and industrial applications. The input voltage range is

from 2.8 V to 5.5 V. The typical application input voltage levels are 3.3 V and 5 V. VANA_OVPis set to 4.3 V

(typical) with 3.3 V input and boost enabled. The boost can be used as a load switch and VANA_OVPis set to 5.8

V (typical) when input voltage is 5 V. VANA_OVPis selected in OTP by VANA_OVP_SEL and is a fixed factory

setting. Table 7-1 lists the output characteristics of the various converters.

Table 7-1. Supply Specification

OUTPUT

SUPPLY

V_OUTRANGE (V)

RESOLUTION (mV)

I_MAXMAXIMUM OUTPUT CURRENT (mA)

Boost

Buck0

4.9 to 5.2

100

600

10 (0.7 V to 0.73 V)

5 (0.73 V to 1.4 V)

20 (1.4 V to 3.36 V)

0.7 to 3.36

3500

10 (0.7 V to 0.73 V)

5 (0.73 V to 1.4 V)

20 (1.4 V to 3.36 V)

Buck1

The LP87702 converters support switching clock synchronization to an external clock connected to CLKIN input.

The external clock can be from 1 MHz to 24 MHz with 1-MHz steps. Alternatively, optional spread spectrum

mode can be enabled to reduce EMI.

LP87702 features include diagnostics, monitoring, and protections for the devices internal and system level

operation, which are the following:

•

Soft start

Input undervoltage lockout

Programmable undervoltage or window (overvoltage and undervoltage) monitoring for the input (from VANA

pin)

•

Programmable undervoltage or window (overvoltage and undervoltage) monitoring for the buck and boost

converter outputs

Two inputs (VMONx) with programmable undervoltage or window (overvoltage and undervoltage) thresholds,

for monitoring external rails in the system

•

One dedicated power-good output (PG0) to which selected monitoring signals can be combined

Second programmable power-good output (PG1), multiplexed with general purpose output (GPO1)

Power good flags with maskable interrupt

Programmable window watchdog

Buck and boost converter overload detection

Thermal warning with two selectable thresholds

Thermal shutdown

LP87702 control interface:

•

Up to three enable inputs ( EN1, EN2, and EN3) with programmable power-up or power-down sequence

control

•

Optional I2C (multiplexed with EN2 and EN3 inputs)

Interrupt signal (nINT) to host

Reset input (NRST)

One dedicated general purpose output (GPO0)

Watchdog disable WD_DIS, multiplexed with CLKIN/GPO2

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7.2 Functional Block Diagram

VANA

Buck0

ILIM Det

Pwrgood

Det

Overload

and SC

nINT

Interrupts

Enable/

Disable,

Delay

Control

Slew-Rate

Control

EN1

Det

Iload ADC

GPO0

Buck1

ILIM Det

Pwrgood

Det

SDA / EN3

SCL / EN2

I2C

Overload

and SC Det

Iload ADC

OTP

EPROM

Registers

Boost

ILIM Det

Pwrgood Det

Digital

Logic

NRST

Overload and

SC Det

Thermal

Monitor

UVLO

Diagnostics

SW

Reset

Ref &

Bias

PG0

Ref &

Bias

Oscillator

PG1/ GPO1

CLKIN / GPO2/ WD_DIS

Window

Watchdog

WD_RESET

VMON1

VMON2

WDI

7.3 Feature Descriptions

7.3.1 Step-Down DC/DC Converters

7.3.1.1 Overview

The LP87702 includes two high-efficiency step-down DC/DC converters. The buck converters deliver 0.7-V

to 3.36-V regulated voltage rails from 2.8-V to 5.5-V input-supply voltage. The converters are designed for

flexibility; most of the functions are programmable, thus optimizing the converter operation for each application:

•

DVS support with programmable slew rate

Automatic mode control based on the loading (PWM or PFM mode)

Forced PWM mode option

Optional external clock input to minimize crosstalk

Optional spread spectrum technique to reduce EMI

Synchronous rectification

Current mode loop with PI compensator

Soft start

Programmable output voltage monitoring with maskable interrupt and selectable connection PG0 or PG1

Average output current sensing (for PFM entry and load current measurement)

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Some of the key parameters that can be programmed through the registers (with default values set by OTP bits):

•

Output voltage

Forced PWM operation

Switch current limit

Output voltage slew rate

Enable and disable delays with ENx pin control

There are two modes of operation for the buck converters, depending on the output current required: pulse width

modulation (PWM) and pulse-frequency modulation (PFM). The converter operates in PWM mode at high load

currents of approximately 520 mA or higher. Lighter output current loads will cause the converter to automatically

switch into PFM mode for reduced current consumption when forced PWM mode is disabled. The forced PWM

mode can be selected to maintain fixed switching frequency at all load currents. When buck is disabled, buck

output is isolated from the input voltage rail. Output has an optional pulldown resistor.

Figure 7-1 shows a block diagram of a single buck converter.

HS FET

CURRENT

SENSE

VIN

FB

POS

CURRENT

LIMIT

RAMP

GENERATOR

V

OUT

-

GATE

CONTROL

ERROR

AMP

SW

+

LOOP

COMP

VOLTAGE

SETTING

SLEW RATE

CONTROL

NEG

CURRENT

LIMIT

POWER

GOOD

+

-

VDAC

ZERO

CROSS

DETECT

LS FET

CURRENT

SENSE

CONTROL

BLOCK

PROGRAMMABLE

PARAMETERS

IADC

GND

Figure 7-1. Detailed Block Diagram Showing One Buck Converter

7.3.1.2 Transition Between PWM and PFM Modes

The LP87702 buck converter operates in PWM mode at load current of about 520 mA or higher. The device

automatically switches into PFM mode for reduced current consumption when forced PWM mode is disabled

(AUTO mode operation) at lighter load current levels. A high efficiency is achieved over a wide output-load

current range by combining the PFM and the PWM modes.

7.3.1.3 Buck Converter Load Current Measurement

Buck load current can be monitored through the I²C registers. The monitored buck converter is selected

with the LOAD_CURRENT_BUCK_SELECT bit in the SEL_I_LOAD register. A write to this selection register

starts a current measurement sequence. The converter is forced to PWM mode during the measurement. The

measurement sequence is 50 µs long at maximum. LP87702 can be configured to give out an I_MEAS_INT

interrupt in the INT_TOP_1 register after the load current measurement sequence is finished. Load current

measurement interrupt can be masked with I_MEAS_MASK bit in TOP_MASK_1 register. The measurement

result can be read from I_LOAD_1 and I_LOAD_2 registers. The buck converter load current measurement

result is 9-bit wide, with 8 LSB bits stored in I_LOAD_1 register and 1 MSB bit stored in I_LOAD_2 register. The

single bit resolution is 20 mA, with a maximum load current value of 10.22 A.

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7.3.2 Boost Converter

The LP87702 device integrates a boost converter with programmable output voltage from 4.9 V to 5.2 V in 0.1

V steps, and input voltage range from 2.8 V to 4 V. The boost converter has flexibility to support wide range of

application conditions:

•

Forced PWM operation

Optional external clock input to minimize crosstalk

Optional spread spectrum technique to reduce EMI

Synchronous rectification

Current mode loop with PI compensator

Soft start

Programmable output voltage monitoring with maskable interrupt and selectable connection to PG0 and PG1

or both

The following parameters can be programmed through the registers, with default values set by the OTP bits

(unless otherwise noted):

•

Output voltage level (BOOST_VSET)

Switch current limit (BOOST_ILIM)

Enable and disable delays when ENx pin control is used (BOOST_DELAY register)

Output pulldown resistor enable or disable when boost is disabled (BOOST_RDIS_EN bit, discharge is

enabled by default)

•

Output voltage monitoring enable or disable and monitoring window thresholds

The boost converter operates in forced PWM mode with fixed switching frequency across all load currents.

When boost is disabled, boost output is isolated from the input voltage rail.

Boost converter supports an alternative operating mode as a bypass or load switch, with input voltage range

from 4.5 V to 5.5 V. Operating mode is selected in OTP and is fixed; changing the mode on-the-fly is not

supported.

7.3.3 Spread-Spectrum Mode

Systems with periodic switching signals may generate a large amount of switching noise in a set of narrowband

frequencies (the switching frequency and its harmonics). The usual solution to reduce noise coupling is to add

EMI-filters and shields to the boards. The LP87702 device supports the spread-spectrum switching frequency

modulation mode that is register controlled. This mode minimizes the need for output filters, ferrite beads, or

chokes. The switching frequency varies between 0.85 × f_SWand f_SWin spread spectrum mode, where f_SWis

switching the frequency selected in the OTP. Figure 7-2 shows how the spread spectrum modulation reduces

conducted and radiated emissions by the converter and associated passive components and PCB traces. This

feature is available only when internal RC oscillator is used (EN_PLL is 0 in PLL_CTRL register) and it is

enabled with the EN_SPREAD_SPEC bit in CONFIG register, and it affects both buck converters and the boost

converter.

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Frequency

Where a fixed frequency converter exhibits large amounts of spectral energy at the switching frequency, the spread spectrum

architecture of the LP87702 spreads that energy over a large bandwidth.

Figure 7-2. Spread Spectrum Modulation

7.3.4 Sync Clock Functionality

The LP87702 device contains a CLKIN input to synchronize buck and boost converters' switching clock with

the external clock. Figure 7-3 shows the block diagram of the clocking and PLL module. Table 7-2 shows how

the external clock is selected and interrupt is generated depending on the EN_PLL bit in PLL_CTRL register

and the external clock availability. The interrupt can be masked with SYNC_CLK_MASK bit in TOP_MASK_1

register. The nominal frequency of the external input clock is set by EXT_CLK_FREQ[4:0] bits in PLL_CTRL

register and it can be from 1 MHz to 24 MHz with 1-MHz steps. The external clock must be inside accuracy limits

(–30%/+10%) for valid clock detection.

The SYNC_CLK_INT interrupt in INT_TOP_1 register is also generated in cases the external clock is expected

but it is not available. These cases are Startup (Read OTP-to-standby transition) when EN_PLL = 1 and buck or

boost converter is enabled (standby-to-active transition) when EN_PLL = 1.

24 MHz

RC

Oscillator

Internal

24 MHz

clock

CLKIN

Detector

Divider

“EXT_CLK

_FREQ“

Clock Select

Logic

1 MHz

CLKIN

24 MHz

PLL

“EN_PLL“

1 MHz

Divider

24

Figure 7-3. Clock and PLL Module

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Table 7-2. PLL Operation

DEVICE

OPERATION MODE

PLL AND CLOCK

DETECTOR STATE

INTERRUPT FOR

EXTERNAL CLOCK

EN_PLL

CLOCK

STANDBY

ACTIVE

0

Disabled

No

Internal RC

Automatic change to internal

RC oscillator when External

clock is not available

When external clock

disappears or appears

STANDBY

ACTIVE

1

Enabled

Automatic change to internal

RC oscillator when External

clock is not available

When external clock

disappears or appears

7.3.5 Power-Up

The power-up sequence for the LP87702 is as follows:

•

VANA (and VIN_Bx) reach minimum recommended levels (V_VANA> VANA_UVLO).

Driving the NRST input high initiates OTP read and enables the system I/O interface. Minimum delay from

the NRST reset input rising edge to I2C write or read access is 1.2 ms.

Device enters STANDBY mode. Watchdog operation starts.

The host can change the default register setting by I²C if needed.

The converters can be enabled or disabled and the GPOx signals can be controlled by ENx pins and by I²C

interface.

•

7.3.6 Buck and Boost Control

7.3.6.1 Enabling and Disabling Converters

The buck converters can be enabled when the device is in STANDBY or ACTIVE state. There are two ways to

enable and disable the buck converters:

•

Using BUCKx_EN bit in BUCKx_CTRL_1 register (BUCKx_EN_PIN_CTRL bit is 00 in BUCKx_CTRL_1

register)

•

Using ENx control pin (BUCKx_EN bit is 1 in BUCKx_CTRL_1 register and BUCKx_EN_PIN_CTRL bit is not

00 in BUCKx_CTRL_1 register)

Similarly there are two ways to enable and disable the boost converter:

•

Using BOOST_EN bit in BOOST_CTRL register (BOOST_EN_PIN_CTRL bit is 0 in BOOST_CTRL register)

Using ENx control pin (BOOST_EN bit is 1 in BOOST_CTRL register and BOOST_EN_PIN_CTRL bit is not

00 in BOOST_CTRL register)

If the ENx control pin is used to enable and disable, then the delay from the control signal rising edge to start-up

is set by BUCKx_STARTUP_DELAY[3:0] bits in BUCKx_DELAY register and BOOST_STARTUP_DELAY[3:0]

bits in BOOST_DELAY register. The delay from falling edge of control signal to shutdown is set by

BUCKx_SHUTDOWN_DELAY[3:0] bits in BUCKx_DELAY register and BOOST_SHUTDOWN_DELAY[3:0] bits

in BOOST_DELAY register. The delays are valid only when ENx pin control is used, not when converters are

enabled by I²C write to BUCKx_EN and BOOST_EN bits.

The control of the converters (with 0-ms delays) is shown in Table 7-3.

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Table 7-3. Converter Control

BUCKx_EN_PIN_C

TRL /

BOOST_EN_PIN_C

TRL

BUCKx_EN /

BOOST_EN

BUCKx OUTPUT VOLTAGE /

BOOST OUTPUT VOLTAGE

EN1 PIN

EN2 PIN

EN3 PIN

Enable or disable

control with BUCKx_EN/

BOOST_EN bit

0

1

Don't Care

00

Don't Care

Disabled

BUCKx_VSET[7:0] / BOOST_VSET[1:0]

Enable or disable control

with EN1 pin

1

01

10

11

Low

Don't Care

Low

Don't Care

Low

Disabled

High

BUCKx_VSET[7:0] / BOOST_VSET[1:0]

Disabled

Enable/disable control

with EN2 pin

Don't Care

High

BUCKx_VSET[7:0] / BOOST_VSET[1:0]

Disabled

Enable or disable control

with EN3 pin

Don't Care

High

BUCKx_VSET[7:0] / BOOST_VSET[1:0]

Figure 7-4 shows how the BUCKx converter is enabled by an ENx pin or by I²C write access. The soft-start

circuit limits the in-rush current during start-up. The output voltage increase rate is typically 30 mV/μsec during

soft start. The output voltage becomes slew-rate controlled when the output voltage rises to 0.35-V level. If

there is a short circuit at the output and the output voltage does not increase above a 0.35-V level in 1 ms, the

converter is disabled, and interrupt is set. When the output voltage rises above the undervoltage power-good

threshold level the BUCKx_PG_INT interrupt flag in the INT_BUCK register is set.

Power-good thresholds are defined by BUCKx_WINDOW bits. A PGOOD_WINDOW bit in PGOOD_CTRL

register sets the detection method for the valid buck output voltage, either undervoltage detection

or undervoltage and overvoltage detection. The powergood interrupt flag can be masked using the

BUCKx_PGR_MASK bit in the BUCK_MASK register when reaching the valid output voltage. The power-

good interrupt flag can also be generated when the output voltage becomes invalid. The interrupt mask for

invalid output voltage detection is set by BUCKx_PGF_MASK bit in BUCK_MASK register. When the window

monitoring (under and overvoltage monitoring) is selected, the mask bits apply when voltage is crossing either

threshold. A BUCKx_PG_STAT bit in BUCK_STAT register shows always the validity of the output voltage; '1'

means valid, and '0' means invalid output voltage.

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BUCKx_VSET[7:0]

Voltage decrease because of load

Voltage

BUCKx_WINDOW[1:0]

Ramp

BUCKx_SLEW_RATE[2:0]

0.6V

0.35V

Time

Resistive pull-down

(if enabled)

Soft start

Enable

0

1

0

1

BUCK_STATUS(BUCKx_STAT)

BUCK_STATUS(BUCKx_PG_STAT)

INT_BUCK(BUCKx_PG_INT)

nINT

1

0

1

0

0 1

0

Powergood

interrupts

Host clears

interrupts

BUCK_MASK(BUCKx_PGF_MASK) = 0

BUCK_MASK(BUCKx_PGR_MASK) = 0

Figure 7-4. Buck Converter Enable and Disable

Figure 7-5 shows how the boost converter is enabled by an ENx pin or by I²C write access. The soft-start circuit

limits the in-rush current during start-up. The output voltage increase rate is less than 100 mV/μsec during soft

start. If there is a short circuit at the output and the output voltage does not reach the input voltage level in 1 ms,

the converter is disabled, and the interrupt is set. When the output voltage reaches the power-good threshold

level, the BOOST_PG_INT interrupt flag in INT_BOOST register is set.

Power-good thresholds are defined by BOOST_WINDOW bits. A PGOOD_WINDOW bit in PGOOD_CTRL

register sets the detection method for the valid boost output voltage, either undervoltage detection or

undervoltage and overvoltage detection. The power-good interrupt flag, when reaching valid output voltage, can

be masked using BOOST_PGR_MASK bit in BOOST_MASK register. The power-good interrupt flag can also

be generated when the output voltage becomes invalid. The interrupt mask for invalid output voltage detection

is set by the BOOST_PGF_MASK bit in BOOST_MASK register. A BOOST_PG_STAT bit in the BOOST_STAT

register always shows the validity of the output voltage; '1' means valid and '0' means invalid output voltage.

The ENx input pins have integrated pulldown resistors. The pulldown resistors are enabled by default and host

can disable those with ENx_PD bits in CONFIG register.

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BOOST_VSET[1:0]

Voltage decrease because of load

Voltage

BOOST_WINDOW[1:0]

Resistive pull-down

(if enabled)

Time

Enable

0

1

0

1

BOOST_STATUS(BOOST_STAT)

BOOST_STATUS(BOOST_PG_STAT)

INT_BOOST(BOOST_PG_INT)

nINT

1

0

1

0

0 1

0

Powergood

interrupts

Host clears

interrupts

BOOST_MASK(BOOST_PGF_MASK) = 0

BOOST_MASK(BOOST_PGR_MASK) = 0

Figure 7-5. Boost Converter Enable and Disable

7.3.6.2 Changing Buck Output Voltage

The output voltage of BUCKx converter can be changed by writing to the BUCKx_VOUT register. The

voltage change for buck converter is always slew-rate controlled, and the slew-rate is defined by the

BUCKx_SLEW_RATE[2:0] bits in BUCKx_CTRL_2 register. The forced PWM mode is used automatically during

a voltage change. When the programmed output voltage is achieved, the mode becomes the one defined by

load current, and the BUCKx_FPWM bit.

Figure 7-6 shows the voltage change and power-good interrupts.

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Ramp for Buck

BUCKx_CTRL2(BUCKx_SLEW_RATE[2:0])

Voltage

BUCKx_VSET

Powergood

Time

1

0

BUCK_STATUS(BUCKx_STAT)

BUCK_STATUS(BUCKx_PG_STAT)

INT_BUCK(BUCKx_PG_INT)

0

1

0

1

0

nINT

Powergood

interrupt

Host clears

interrupt

Powergood

interrupt

Host clears

interrupt

BUCK_MASK(BUCKx_PGF_MASK)=0

BUCK_MASK(BUCKx_PGR_MASK)=0

Figure 7-6. Buck Output Voltage Change

7.3.7 Enable and Disable Sequences

The LP87702 device supports programmable start-up and shutdown sequencing. An enable control signal

is used to initiate the start-up sequence and to turn off the device according to the programmed shutdown

sequence. Up to three enable inputs are available: EN1 is a dedicated enable input; EN2 and EN3 are

multiplexed with I2C interface. The buck converter is selected for sequence control with:

•

BUCKx_CTRL_1(BUCKx_EN) = 1

BUCKx_CTRL_1(BUCKx_EN_PIN_CTRL) = 0x1 or 0x2 or 0x3, for EN1 or EN2 or EN3 control, respectively

BUCKx_VOUT.(BUCKx_VSET[7:0]) = Required voltage when EN pin is high

The delay from rising edge of EN pin to the converter enable is set by

BUCKx_DELAY(BUCKx_STARTUP_DELAY[3:0]) bits and

•

The delay from falling edge of EN pin to the converter disable is set by

BUCKx_DELAY(BUCKx_SHUTDOWN_DELAY[3:0])

In the same way the boost converter is selected for delayed control with:

•

BOOST_CTRL(BOOST_EN) = 1

BOOST_CTRL(BOOST_EN_PIN_CTRL) = 0x1 or 0x2 or 0x3, for EN1. EN2, or EN3 control (respectively)

BOOST_CTRL(BOOST_VSET[2:0]) = Required voltage when EN pin is high

The delay from rising edge of EN pin to the converter enable is set by

BOOST_DELAY(BOOST_STARTUP_DELAY[3:0]) bits and

•

The delay from falling edge of EN pin to the converter disable is set by

BOOST_DELAY(BOOST_SHUTDOWN_DELAY[3:0])

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An example of start-up and shutdown sequences for buck converters are shown in Figure 7-7. The start-up and

shutdown delays for Buck0 converter are 1 ms and 4 ms and for Buck1 converter 3 ms and 1 ms. The delay

settings are used only for enable or disable control with the EN signal.

Typical sequence

ENx

Internal

BUCK0 enable

1 ms

4 ms

Internal

BUCK1 enable

3 ms

1 ms

Sequence with short EN low and high periods

ENx

Startup cntr

0

1

0

1

2

3

4

5

6

0

2

Shutdown cntr

0

1

0

1

0

1

2

3

4

5

Internal

BUCK0 enable

1 ms

4 ms

Internal

BUCK1 enable

3 ms

1 ms

Figure 7-7. Start-up and Shutdown Sequencing Example

7.3.8 Window Watchdog

Figure 7-8 shows the LP87702 watchdog's operation (for an example, when the ENx pin is used for controlling

power sequence and ENx pin is active).

WDI is the watchdog function input pin, and WD_RESET is the reset output. The WDI pin needs pulsed

within a certain timing window to avoid a watchdog expiration. The minimum pulse width is 100 µs. The

watchdog expiration always causes a reset pulse at WD_RESET output, otherwise the device behavior after

watchdog expiration is programmable. WD_RESET output polarity and mode, push-pull or open drain, are also

programmable.

Watchdog default settings are read from OTP during device start-up. Default settings in WD_CTRL_1 and

WD_CTRL_2 register can be over-written through the I2C (as long as WD_LOCK bit is not set to 1). Writing

WD_LOCK = 1 in WD_CTRL_2 register locks watchdog settings until NRST input is driven low, power cycle or

register reset by SW_RESET.

Table 7-4 shows how the long open, close, and open window periods are independently programmable. The

watchdog enters the WD Reset state when the long open or open window expires before the WDI input is

received. Also, the watchdog enters the WD Reset when the WDI is received during close window. Long open

period can be extended by a I2C write to WD_CTRL_1 or WD_CTRL_2 register; the register access initializes

the long open counter and the long open period restarts (except in Stop mode).

LP87702 behavior after WD expiration is programmable:

•

When WD_RESET_CNTR_SEL = 00, system restart is disabled and converters are maintained ON.

WD_RESET pin is active for 10 ms. Watchdog returns to Long Open mode.

•

When WD_RESET_CNTR_SEL = 01 (restart after first reset pulse), LP87702 performs shutdown sequence

followed by start-up sequence so the converters are disabled and re-enabled according to the OTP

programmed sequences. The device reloads OTP defaults when WD_EN_OTP_READ = 1 during start-up.

Settings valid before shutdown are maintained when the WD_EN_OTP_READ = 0. WD_RESET output pin is

active for a period of (10 ms + maximum shutdown delay). Maximum shutdown delay can be selected as 7.5

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ms (SHUTDOWN_DELAY_SEL = 0) or 15 ms (SHUTDOWN_DELAY_SEL = 1). After the restart watchdog

returns to Long Open mode.

•

The status bit (WD_SYSTEM_RESTART_FLAG) is set to indicate that a system restart has happened. The

status can be cleared by writing 1 to WD_CLR_SYSTEM_RESTART_FLAG. WD_RESET_CNTR_SEL can

be set to 10 or 11 to select restart after 2 or 4 WD expirations, respectively. The current status of the

reset counter is available in WD_RESET_CNTR_STATUS. The reset counter can be cleared by writing

WD_CLR_RESET_CNTR to 1.

Watchdog settings in WD_CTRL_1 and WD_CTRL_2 registers are locked by setting the WD_LOCK bit.

WD_SYSTEM_RESTART_FLAG and WD_RESET_CNTR_STATUS can be cleared even if WD_LOCK = 1.

Description above is for a case where ENx pin is used for controlling power sequence and ENx pin is active.

Watchdog behavior can be slightly different depending on the OTP settings and the ENx pin state, which follows:

•

When the ENx pin is used for controlling the power sequence and the ENx pin is not active, the shutdown

sequence cannot be performed. WD_RESET pulse length is fixed 31 ms.

•

There is no OTP defined power sequence when the ENx pins are not used for power sequence control, and

all converters and GPOs are enabled through the I2C. WD expiration does not cause a converter disable

or enable sequence even when the OTP settings for the watchdog enable restart. In this case WD_RESET

pulse is 11 ms.

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NRST low OR

VANA < VANA_UVLO

(WD_SYSTEM_RESTART_FLAG = 0

OR

WD_SYSTEM_RESTART_FLAG_MODE = 0)

AND

Stop

Shutdown

WD_EN_OTP_READ = 1

NRST high AND

VANA > VANA_UVLO

(WD_SYSTEM_RESTART_FLAG = 0

OR

WD_SYSTEM_RESTART_FLAG_MODE = 0)

AND

WD_EN_OTP_READ = 0

Read OTP

WD_SYS_RESTART_FLAG_MODE = 1

WD_EN_OTP_READ = 1

Shutdown

Sequence

WD_RESET output

active for (7.5ms +10ms)

or (15ms+10ms)

Release ENx

pin gating

WD_EN_OTP_READ = 0

Set

WD_SYSTEM_

RESTART_FLAG = 1

Long Open

WD_RESET output

active for 10ms

Restart Enabled AND

Reset Counter >= Counter Select

I2C Writing to WD Control Register

(from all states except Stop)

WDI Rising

Restart Disabled OR

Reset Counter < Counter Select

LongOpenTime Expired

WD Reset

Increase Reset Counter value,

WDI Rising

Close

OpenTime Expired

CloseTime Expired

WDI Rising

Open

Figure 7-8. Watchdog Operation

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Table 7-4. Watchdog Window Periods

CONTROL BIT

DEFAULT

VALUES

00 – 200 ms

01 – 600 ms

10 – 2000 ms

11 – 5000 ms

WD_LONG_OPEN_TIME

OTP

00 – 10 ms

01 – 20 ms

10 – 50 ms

11 – 100 ms

WD_CLOSE_TIME

7.3.9 Device Reset Scenarios

There are four reset methods implemented on the LP87702:

•

Software reset with the SW_RESET bit in the RESET register

NRST input signal low

Undervoltage lockout (UVLO) reset from VANA supply

Watchdog expiration (depending on the watchdog settings)

A SW reset occurs when the SW_RESET bit is set to 1. The bit is automatically cleared after writing. Figure

7-14shows how this event disables all the converters immediately, drives GPO signals low, resets all the register

bits to the default values and the OTP bits are loaded. I²C interface is not reset during a software reset. The host

must wait at least 1.2 ms after writing SW reset until making a new I2C read or write to the device.

If VANA supply voltage falls below the UVLO threshold level or the NRST signal is set low, then all the

converters are disabled immediately, the GPOx signals are driven low, and all the register bits are reset to the

default values. When the VANA supply voltage rises above the UVLO threshold level and the NRST signal rises

above the threshold level, the OTP bits are loaded to the registers and a start-up is initiated according to the

register settings. The host must wait at least 1.2 ms before reading or writing to the I2C interface.

Depending on the watchdog settings, the watchdog expiration can reset the device to the OTP default values.

7.3.10 Diagnostics and Protection Features

The LP87702 provides four levels of protection features:

•

Input and output voltage information. Non-valid voltage sets interrupt or PGx signal:

– Validity of the output voltage of BUCK or BOOST converters

– Validity of VANA, VMON1, and VMON2 input voltages

Warnings causing interrupt:

– Peak current limit detection in BUCK or BOOST converters

– Thermal warning

Protection events which are disabling the converters:

– Short-circuit and overload protection for BUCK and BOOST converters

– Input overvoltage protection (VANA_OVP

)

– Watchdog expiration (optional, depends on the watchdog settings)

– Thermal shutdown

•

Protection events which are causing the device to shutdown:

– Undervoltage lockout (VANA_UVLO

)

Protections not causing interrupt or converter disable:

– Negative current limit detection in the BUCK or BOOST converters

7.3.10.1 Voltage Monitorings

The LP87702 device has programmable voltage monitoring for the BUCKx and BOOST converter output

voltages and for VANA, VMON1, and VMON2 inputs. Monitoring of each signal is independently enabled in

the PGOOD_CTRL register. Voltage monitoring can be under-voltage monitoring only (PGOOD_WINDOW =

0) or overvoltage and undervoltage monitoring (PGOOD_WINDOW = 1). This selection is common for all

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enabled monitorings. Section 7.3.10.3describes how the enabled monitoring signals are combined to generate

power-good (PG0 and PG1) and interrupts. Monitoring comparators have a dedicated reference and bias block,

which is independent of the main reference and bias block.

Nominal level for the output voltage of BUCKx converter is set with BUCKx_VSET in the BUCKx_VOUT

register. Overvoltage and undervoltage detection levels, with respect to nominal level, are selected with

BUCKx_WINDOW as ± 30 mV, ± 50 mV, ± 70 mV or ± 90 mV. Nominal level for the output voltage of the

BOOST converter is set with BOOST_VSET in the BOOST_CTRL register. Available levels are 4.9 V, 5 V,

5.1 V, and 5.2 V. Overvoltage and undervoltage detection levels, with respect to nominal level, are selected

with BOOST_WINDOW as ± 2%, ± 4%, ± 6% or ± 8%. Converter monitoring window selection bits are in the

PGOOD_LEVEL_3 register.

Input voltage of LP87702 is monitored at the VANA pin. Nominal level can be selected as 3.3 V or 5 V with the

VANA_THRESHOLD bit. Overvoltage and undervoltage detection levels are selected with VANA_WINDOW as

(nominal). VANA_THRESHOLD and VANA_WINDOW are set in the PGOOD_LEVEL_2 register.

VMON1 and VMON2 inputs can be used for monitoring external rails in the system. VMONx settings are

defined in the PGOOD_LEVEL_1 and PGOOD_LEVEL_2 registers. Nominal value for the input level of VMONx

is selected with VMONx_THRESHOLD, between 0.65 V to 1.8 V. Higher voltage levels or levels not directly

supported can be monitored using an external resistor divider. In this case VMONx_THRESHOLD must be set

as 0.65 V to have a high-impedance input, and the resistor divider must scale the monitored level down to 0.65 V

at the VMONx pin. Overvoltage and undervoltage detection levels are selected with VMONx_WINDOW as ± 2%,

± 3%, ± 4% or ± 6%.

See Section 6 for more details on the accuracy of the monitoring windows and deglitch filtering.

7.3.10.2 Interrupts

The LP87702 sets the flag bits indicating what protection or warning conditions have occurred, and the nINT pin

is pulled low. The nINT output pin is driven high after all the flag bits and pending interrupts are cleared.

Fault detection is indicated by the RESET_REG_INT interrupt flag bit set in the INT_TOP_2 register after the

start-up event.

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Table 7-5. Summary of Interrupt Signals

EVENT

SAFE STATE

INTERRUPT BIT

INTERRUPT MASK

STATUS BIT

RECOVERY/INTERRUPT

CLEAR

Buck current limit

triggered (20-µs

debounce)

No effect

BUCK_INT = 1

BUCKx_ILIM_INT = 1

BUCKx_ILIM_MASK

BUCKx_ILIM_STAT

Write 1 to the

BUCKx_ILIM_INT bit

Interrupt is not cleared if the

current limit is active.

Boost current limit

triggered

No effect

BOOST_INT = 1

BOOST_ILIM_INT = 1

BOOST_ILIM_MASK

BOOST_ILIM_STAT

N/A

Write 1 to the

BOOST_ILIM_INT bit.

Interrupt is not cleared if the

current limit is active.

Buck short circuit

(V_VOUT< 0.35V at

1 ms after enable)

or Overload (V_VOUT

decreasing below 0.35

V during operation, 1 ms

debounce)

Converter disable

BUCKx_INT = 1

BUCKx_SC_INT = 1

N/A

Write 1 to the BUCKx_SC_INT

bit.

Boost short circuit

Converter disable

No effect

BOOST_INT = 1

BOOST_SC_INT = 1

N/A

Write 1 to the BOOST_SC_INT

bit.

Thermal warning

TDIE_WARN_INT) = 1

TDIE_WARN_MASK

TDIE_WARN_STAT

Write 1 to the

TDIE_WARN_INT bit.

Interrupt is not cleared if

the temperature is above the

thermal warning level.

Thermal shutdown

VANA overvoltage

All converters disabled

immediately and GPOx

set to low

TDIE_SD_INT = 1

OVP_INT

N/A

TDIE_SD_STAT

OVP_STAT

Write 1 to TDIE_SD_INT bit

Interrupt is not cleared if

temperature is above thermal

shutdown level

All converters disabled

immediately and GPOx

set to low

Write 1 to the OVP_INT bit.

Interrupt is not cleared if the

VANA voltage is above the

VANA_OVPlevel.

(VANA_OVP

)

Buck power-good,

output voltage becomes

valid.

No effect

BUCK_INT = 1

BUCKx_PG_INT = 1

BUCKx_PGR_MASK

BUCKx_PGF_MASK

BOOST_PGR_MASK

BOOST_PGF_MASK

VMON1_PGR_MASK

VMON1_PGF_MASK

VMON2_PGR_MASK

VMON2_PGF_MASK

VANA_PGR_MASK

VANA_PGF_MASK

BUCKx_PG_STAT

BOOST_PG_STAT

VMON1_PG_STAT

VMON2_PG_STAT

VANA_PG_STAT

Write 1 to the BUCKx_PG_INT

bit.

Buck power-good,

output voltage becomes

invalid

BUCK_INT = 1

BUCKx_PG_INT = 1

Write 1 to the BUCKx_PG_INT

bit.

Boost power-good,

output voltage becomes

valid.

BOOST_INT = 1

BOOST_PG_INT = 1

Write 1 to the BOOST_PG_INT

bit.

Boost power-good,

output voltage becomes

invalid.

BOOST_INT = 1

BOOST_PG_INT = 1

Write 1 to the BOOST_PG_INT

bit.

VMON1 power-good,

input voltage becomes

valid.

DIAG_INT = 1

VMON1_PG_INT = 1

Write 1 to the VMON1_PG_INT

bit.

VMON1 power-good,

input voltage becomes

invalid.

DIAG_INT = 1

VMON1_PG_INT = 1

Write 1 to the VMON1_PG_INT

bit.

VMON2 power-good,

input voltage becomes

valid.

DIAG_INT = 1

VMON2_PG_INT = 1

Write 1 to the VMON2_PG_INT

bit.

VMON2 power-good,

input voltage becomes

invalid.

DIAG_INT = 1

VMON2_PG_INT = 1

Write 1 to the VMON2_PG_INT

bit.

VANA power-good,

input voltage becomes

valid.

DIAG_INT = 1

VANA_PG_INT = 1

Write 1 to the VANA_PG_INT

bit.

VANA power-good,

input voltage becomes

invalid.

DIAG_INT = 1

VANA_PG_INT = 1

Write 1 to the VANA_PG_INT

bit.

External clock appears

or disappears.

No effect to converters

No effect

SYNC_CLK_INT⁽¹⁾

I_MEAS_INT = 1

N/A

SYNC_CLK_MASK

I_MEAS_MASK

N/A

SYNC_CLK_STAT

Write 1 to the SYNC_CLK_INT

bit.

Load current

measurement ready

N/A

Write 1 to the I_MEAS_INT bit.

Supply voltage

VANA_UVLOtriggered

(VANA falling)

Immediate shutdown,

registers reset to default

values

N/A

Supply voltage

VANA_UVLOtriggered

(VANA rising)

Start-up, registers reset

to default values and

OTP bits loaded

RESET_REG_INT = 1

RESET_REG_MASK

N/A

Write 1 to the

RESET_REG_INT bit.

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Table 7-5. Summary of Interrupt Signals (continued)

EVENT

SAFE STATE

INTERRUPT BIT

INTERRUPT MASK

STATUS BIT

RECOVERY/INTERRUPT

CLEAR

Software requested

reset

Immediate shutdown

followed by powerup,

registers reset to default

values

RESET_REG_INT = 1

RESET_REG_MASK

N/A

Write 1 to the

RESET_REG_INT bit.

(1) Interrupt generated during the Clock Detector operation and in case the Clock is not available when the Clock Detector is enabled.

7.3.10.3 Power-Good Information to Interrupt, PG0, and PG1 Pins

LP87702 supports both interrupt based indication of the power-good levels for various voltage settings and

uses two power-good signals, PG0 and PG1. The selection of monitored signals is independent for the interrupt

(nINT) and PG0 and PG1 signals. Each signal can include the following:

•

The output voltage of one or both BUCKx converters

The output voltage of the BOOST converter

Input voltage of VANA

Input voltage of VMON1 and VMON2 or both

Thermal warning

Figure 7-9 shows the block diagram for power-good connections to PG0 and PG1 pins and interrupt.

Monitored signals are enabled in the PGOOD_CTRL register. Converter output voltage monitoring (not current

limit monitoring) can be selected for the indication. Monitoring is enabled by the EN_PGOOD_BUCKx and

EN_PGOOD_BOOST bits. The monitoring is automatically masked to prevent it from forcing PGx inactive or

causing an interrupt when a converter is disabled. Also, monitoring of VANA, VMON1, and VMON2 inputs can

be independently enabled through the PGOOD_CTRL register. The type of voltage monitoring for the PGx

signals and nINT is selected by the PGOOD_WINDOW bit. Only the undervoltage is monitored if the bit is 0

and the undervoltage and overvoltage are monitored if the bit is 1. See Section 7.3.10.1 for voltage monitoring

thresholds.

Monitoring interrupts from all the output rails, input rails, and thermal warning are combined to the nINT pin.

Dedicated mask bits are used to select which interrupts control the state of the nINT pin. See Table 7-5 for

summary of the interrupts, mask bits, and interrupt clearing.

Similarly, enabled monitoring signals from all the output rails, input rails, and thermal warning are combined to

PG0 and PG1 output pins. Register bits (SEL_PGx_x in PG0_CTRL and PG1_CTRL) select which of the signals

control the state of PG0 and PG1, respectively. The polarity and the output type (push-pull or open-drain) of PG0

and PG1 are selected by the PGx_POL and PGx_OD bits in the PG_CTRL register.

PGx is only active or asserted when all monitored input voltages and all output voltages of the monitored and

enabled converters are within the specified tolerance of the set target value.

PGx is inactive or de-asserted if any of the monitored input voltages or output voltages of the monitored and

enabled converters are outside the specified tolerance of the set target value.

When PGx_RISE_DELAY = 1, PGx is set as active or asserted with 11 ms delay from the point of time

where all the enabled power resource output voltages are within the specified tolerance for each requested or

programmed output voltage.

Thermal shutdown and VANA overvoltage protection events force the PGx to the default state (the PGx are

driven low, assuming the PGx polarity set in the OTP is active high).

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Mask

RisMinagsk

INT

RisMinagsk

Mask

RisMinagsk

FallMinagsk

RisMinagsk

FallMinagsk

Boost

Powergood

RisMinagsk

Rising

FallMinagsk

EN_PGOOD_BOOST

Status

FallMinagsk

Buck0

Powergood

Status

Falling

Status

EN_PGOOD_BUCK0

EN_PGOOD_BUCK1

EN_PGOOD_VANA

EN_PGOOD_VMON1

EN_PGOOD_VMON2

nINT

Status

Buck1

Powergood

VANA

VMON1

VMON2

VANA

Powergood

Mask

INT

VMON1

Powergood

Status

VMON2

Powergood

Thermal

Warn

SEL_PG0_TWARN

SEL_PG0_VMON2

SEL_PG0_VMON1

SEL_PG0_VANA

SEL_PG0_BUCK1

SEL_PG0_BUCK0

SEL_PG0_BOOST

PG0

PP/OD

Polarity

PG1/GPO1

PP/OD

PG0 CONTROL

PG1 CONTROL

GPO1_SEL

GPO1

Figure 7-9. Block Diagram of Power-Good Connections

LP87702 power-good detection has two operating modes selected in the OTP: gated (that is, unusual) or

continuous (that is, invalid) mode of operation. These modes are described in Section 7.3.10.3.1 and in Section

7.3.10.3.2.

7.3.10.3.1 PGx Pin Gated (Unusual) Mode

The PGx signal detects unexpected or unusual situations in this mode. Mode is selected by setting the

PGx_MODE bit to 0 in the PG_CTRL register.

For the gated mode of operation, the PGx behaves as follows:

•

PGx is set to active or asserted state upon exiting the OTP configuration as an initial default state.

The PGx status is active or asserted during an 800-μs gated time period from the enable activation for each

enabled rail, thereby gating-off the status indication.

•

The PGx state typically remains active or asserted for normal conditions during normal power-up sequencing

and requested voltage changes.

The PGx status could change to inactive or de-asserted after an 800-μs gated time period if any output

voltage is outside of regulation range during an abnormal power-up sequencing and requested voltage

changes.

•

Using the gated mode of operation could allow the PGx signal to initiate an immediate power shutdown

sequence if the PGx signal is wired-OR with signal connected to the EN input. This type of circuit

configuration provides a smart PORz function for processor that eliminates the need for additional

components to generate PORz upon start-up and to monitor voltage levels of key voltage domains.

PGx signal is set inactive if the output voltage of a monitored buck or boost converter is invalid or the output

voltage is not valid at 800 µs from the enable of the converter, which should be considered when selecting the

BUCKx_SLEW_RATE setting. Keep the sum of the soft start time and slew rate controlled part of the voltage

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ramp below 800 µs to avoid PGx triggering at start-up. In addition, the PGx is inactive when the invalid input

voltage at VANA, VMON1, or VMON2 pin is detected.

Detected fault sets the corresponding fault bit in PG0_FAULT or in PG1_FAULT register. The detected fault must

be cleared to continue the PGx monitoring. The over-voltage and thermal faults are cleared by writing 1 to the

corresponding interrupt bits in INT_TOP_1 register. Converter, VMONx and VANA faults are cleared by writing 1

to the corresponding register bit in INT_BUCK, INT_BOOST, and INT_DIAG register, respectively. An example

of the PGx pin operation in gated mode is shown in Figure 7-10 and the different use cases for the PGx signal

operation are summarized in Table 7-6.

V_(VANA)

VANA_UVLO

Shut

down

Read

OTP

Standby

Active

State

PGx pin

Clear fault

EN

4ms

EN (Buck1)

VOUT (Buck1)

800us Timer

Powergood (Buck1)

EN (Boost)

2ms

800us Timer

VOUT (Boost)

Powergood (Boost)

Figure 7-10. PGx Pin Operation in Gated Mode.

7.3.10.3.2 PGx Pin Operation in Continuous Mode

In this mode the PGx signal shows the validity of the requested voltages continuously. Mode is selected by

setting the PGx_MODE bit to 1 in the PG_CTRL register.

For the continuous mode of operation, the PGx behaves as follows:

•

PGx is set to active or asserted state upon exiting the OTP configuration as an initial default state.

PGx is set to inactive or de-asserted as soon as the converter is enabled.

PGx status begins indicating the output voltage regulation status immediately and continuously.

PGx state changes between inactive or deasserted and active or asserted during power-up sequencing

and requested voltage changes, depending on the output voltages being outside or inside of the regualtion

ranges.

When an invalid output voltage of monitored converter is detected, the corresponding bit in the PG0_FAULT

or PG1_FAULT register is set to 1 and the PGx signal becomes inactive. The PG0_FAULT and PG1_FAULT

register bits are latched and maintain the fault information until host clears the fault bit by writing 1 to the bit.

The PGx signal also indicates the interrupts from VANA, VMON1, and VMON2 inputs and thermal warning and

shutdown. All are cleared by clearing the interrupt bits.

The PGx signal is set inactive when the converter voltage is transitioning from one target voltage to another.

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The source for the fault can be read from PGx_FAULT register when PGx signal becomes inactive. If the invalid

output voltage becomes valid again the PGx signal becomes active. Thus the PGx signal shows all the time if

the monitored output voltages are valid. Figure 7-11 shows an example of the PGx pin operation in continuous

mode.

The PGx signal can also be configured so that it maintains the inactive state even when the monitored outputs

are valid, but there are PG_FAULT_x bits pending clearance. This type of operation is selected by setting the

PGOOD_FAULT_GATES_PGx bit to 1.

V_(VANA)

VANA_UVLO

Shut

down

Read

OTP

Standby

Active

State

PGx pin

EN

4ms

EN (Buck1)

VOUT (Buck1)

Powergood (Buck1)

EN (Boost)

2ms

VOUT (Boost)

Powergood (Boost)

Figure 7-11. PGx Pin Operation in Continuous Mode

7.3.10.3.3 Summary of PG0, PG1 Gated, and Continuous Operating Modes

Table 7-6 summarizes the PGx behavior in different application scenarios, for the gated and continuous

operating modes.

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Table 7-6. PGx Operation

PGx SIGNAL^{(1) (2)}

STATUS / USE CASE

CONDITION

GATED MODE

PGx_MODE = 0

CONTINUOUS MODE

PGx_MODE = 1

Device start-up

Until device state is STANDBY

EN_PGOOD_x = 0

Low

OK

Converter not selected for PGx

monitoring

OK

Converter selected for PGx

monitoring and disabled by host

BUCKx_EN / BOOST_EN = 0 OR

(Pin ctrl AND EN = 0)

OK

Converter start-up delay ongoing

EN = 1

NOK

Converter start-up until valid

output voltage reached

Valid output voltage reached in 800

µs

Converter start-up until valid

output voltage reached

Valid output voltage not reached at

800 µs

NOK

OK

NOK

OK

Output voltage within window

limits after start-up

Must be inside limits longer than

debounce time

If spikes are outside voltage

monitoring threshold(s) longer than

debounce time

Output voltage spikes (over/

undervoltage)

NOK

OK (if new voltage reached in 800

µs)

NOK after 800 µs (if new voltage

not reached at 800 µs)

Voltage setting change, output

voltage ramp

Output voltage within window

limits after voltage change

Must be inside limits longer than

debounce time

OK

Converter shutdown delay

ongoing

Buck converter disabled by host,

slew-rate controlled ramp down

ongoing

OK

Converter disabled by host,

pulldown resistor active (if

selected)

Faulty converter disabled by short-

circuit detection

BUCKx_SC_INT / BOOST_SC_INT

= 1

Converter short-circuit interrupt

pending (converter selected for

PGx monitoring)

NOK

Converters disabled by thermal

shutdown detection

Thermal shutdown interrupt

pending

TDIE_SD_INT = 1

Converters disabled by overvoltage

detection

Input (VANA) overvoltage

interrupt pending

NOK

Low

NOK

Low

OVP_INT = 1

Supply voltage below VANA_UVLO

(1) NOK (Not OK) means faulty situation. PGx pin is inactive if at least one NOK situation is detected.

(2) PGx pin is generated from PG_FAULT register bits and INT_TOP_1 register bits TDIE_SD_INT, OVP_INT and

INT_TOP_2(RESET_REG_INT) bit.

7.3.10.4 Warning Interrupts for System Level Diagnostics

7.3.10.4.1 Output Power Limit

The buck converters have programmable output peak current limits. The limits are individually programmed for

both converters with BUCKx_ILIM[2:0] bits. If the load current is increased so that the current limit is triggered,

the converter continues to regulate to the limit current level (current peak regulation). The voltage may decrease

if the load current is higher than limit current. If the current regulation continues for 20 µs, the LP87702 device

sets the BUCKx_ILIM_INT bit and pulls the nINT pin low. The host processor can read the BUCKx_ILIM_STAT

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bits to see if the converter is still in peak current regulation mode. During startup or output voltage ramp (output

voltage change has been programmed) no interrupt is generated.

If the load is so high that the output voltage decreases below a 350-mV level, the LP87702 device disables

the converter and sets the BUCKx_SC_INT bit. The interrupt is cleared when the host processor writes 1 to

BUCKx_SC_INT bit. Figure 7-12 shows the Buck overload situation.

Regulator disabled by

digital

New startup if

enable is valid

Voltage

VOUTx

350 mV

Resistive

pull-down

1 ms

Time

Current

ILIMx

Time

20 µs

0

1

0

INT_BUCK(BUCKx_ILIM_INT)

INT_BUCK(BUCKx_SC_INT)

BUCK_STAT(BUCKx_STAT)

nINT

1

0

1

Host clearing the interrupt by writing to flags

Figure 7-12. Buck Overload Situation

The boost converter has programmable output peak current limits. The limits are set with the BOOST_ILIM bits.

If the load current is increased so that the current limit is triggered, the converter continues to regulate to the limit

current level (current peak regulation). The voltage may decrease if the load current is higher than limit current. If

the current regulation continues for 64 µs, the LP87702 device sets the BOOST_ILIM_INT bit and pulls the nINT

pin low. The host processor can read the BOOST_ILIM_STAT bits to see if the converter is still in peak current

regulation mode.

If the load is so high that the output voltage decreases 150 mV (typical) below the input voltage level, then the

converter is disabled after 1 ms. If the output voltage decreases to 2.5 V, boost stops switching. After 1 ms the

deglitch time boost is fully disabled and the interrupt BOOST_SC_INT bit is set. The interrupt is cleared when

the host processor writes 1 to the BOOST_SC_INT bit. Figure 7-13 shows the Boost overload situation.

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Converter disabled

by digital

New startup if

enable is valid

Voltage

VOUTx

VIN

2.5 V

1ms

Resistive

pull-down

Time

Current

ILIMx

64 ms

0

1

0

INT_BOOST(BOOST_ILIM_INT)

INT_BOOST(BOOST_SC_INT)

BOOST_STAT(BOOST_STAT)

nINT

1

0

1

Host clearing the interrupt by writing to flags

Figure 7-13. Boost Overload Situation

The buck converters have a fixed current limit for negative output peak current (I_{LIM_NEG}). When the negative coil

current increases, it is limited below I_{LIM_NEG}, the converter continues to operate and no interrupt is generated.

The boost converter's negative peak current limit operation is similar and the limit value is 1.4 A (typical).

7.3.10.4.2 Thermal Warning

The LP87702 device includes a protection feature against over-temperature by setting an interrupt for the host

processor. The thermal warning's threshold level is selected with the TDIE_WARN_LEVEL bit.

If the LP87702 device temperature increases above the thermal warning level, the device sets the

TDIE_WARN_INT bit and pulls the nINT pin low. The status of the thermal warning can be read from the

TDIE_WARN_STAT bit and the interrupt is cleared by writing 1 to the TDIE_WARN_INT bit. The thermal warning

interrupt can be masked by setting the TDIE_WARN_MASK bit to 1.

7.3.10.5 Protections Causing Converter Disable

If the converter is disabled because of protection or fault (short-circuit protection, thermal shutdown, overvoltage

protection, or undervoltage lockout), the output power FETs are set to high-impedance mode, and the output

pulldown resistor is enabled (if enabled with BUCKx_RDIS_EN and BOOST_RDIS_EN bits). The turnoff time

of the output voltage is defined by the output capacitance, load current, and the resistance of the integrated

pulldown resistor. The pulldown resistors are active as long as the VANA voltage is above the 1.2-V level

(approximately).

7.3.10.5.1 Short-Circuit and Overload Protection

A short-circuit protection feature allows the LP87702 to protect itself and external components against short

circuiting at the output or against overloading during start-up. A short-circuit at the buck converter output is

detected during start-up when the output voltage is below 350 mV (typical) 1 ms after the buck converter is

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enabled. The fault threshold is 150 mV (typical) below the input voltage level for boost. Boost converter is

disabled if the output voltage is below the threshold level 1 ms after the boost converter is enabled.

In a similar way, the overload situation is protected during normal operation. If the feedback-pin voltage of the

buck converter falls below 0.35 V and remains below the threshold level for 1 ms, the buck converter is disabled.

If the output voltage of the boost converter decreases 150 mV below the input voltage level, the converter is

disabled after 1 ms. If the output voltage decreases to 2.5 V, the boost is disabled immediately.

The BUCKx_SC_INT and the BUCK_INT bits are set to 1, the BUCKx_STAT bit is set to 0, and the nINT

signal is pulled low in the buck converter, the short-circuit, and overload situations. The BOOST_SC_INT and

the BOOST_INT bits are set to 1, the BOOST_STAT bit is set to 0, and the nINT signal is pulled low in the

boost converter, short-circuit, and overload situations. The host processor clears the interrupt by writing 1 to

the BUCKx_SC_INT or BOOST_SC_INT bit. The converter makes a new start-up attempt upon clearing the

interrupt, if the converter is in the enabled state.

7.3.10.5.2 Overvoltage Protection

The LP87702 device monitors the input voltage from the VANA pin in the standby and active operation modes.

If the input voltage rises above the VANA_OVPvoltage level, all the converters are disabled immediately (without

switching ramp or shutdown delays), the pulldown resistors discharge the output voltages (BUCKx_RDIS_EN

= 1 and BOOST_RDIS_EN = 1), the GPOs are set to the logic low level, the nINT signal is pulled low, the

OVP_INT bit is set to 1, and BUCKx_STAT and BOOST_STAT bits are set to 0. The host processor clears the

interrupt by writing 1 to the OVP_INT bit. If the input voltage is above over-voltage detection level, the interrupt

is not cleared. The host can read the status of the overvoltage from the OVP_STAT bit. Converters cannot be

enabled as long as the input voltage is above over-voltage detection level or the overvoltage interrupt is pending.

7.3.10.5.3 Thermal Shutdown

The LP87702 has an overtemperature protection function that operates to protect itself from short-term misuse

and overload conditions. The converters are disabled immediately (without switching ramp or shutdown delays),

the TDIE_SD_INT bit is set to 1, the nINT signal is pulled low, and the device enters STANDBY when the

junction temperature exceeds around 150°C. The nINT is cleared by writing 1 to the TDIE_SD_INT bit. If

the temperature is above thermal shutdown level, the interrupt is not cleared. The host can read the status

of the thermal shutdown from the TDIE_SD_STAT bit. Converters cannot be enabled as long as the junction

temperature is above the thermal shutdown level or the thermal shutdown interrupt is pending.

7.3.10.6 Protections Causing Device Power Down

7.3.10.6.1 Undervoltage Lockout

The buck and boost converters are disabled immediately (without switching ramp or without any shutdown

delays), and the output capacitor is discharged using the pulldown resistor, and the LP87702 device enters

SHUTDOWN when the input voltage falls below VANA_UVLOat the VANA pin. The device powers up to STANDBY

state when the V_(VANA)voltage is above the VANA_UVLOthreshold level.

If the reset interrupt is unmasked by default (RESET_REG_MASK = 0 in TOP_MASK_2 register), the

RESET_REG_INT interrupt in the INT_TOP_2 register indicates that the device has been in SHUTDOWN. The

host processor must clear the interrupt by writing 1 to the RESET_REG_INT bit. If the host processor reads the

RESET_REG_INT flag after detecting an nINT low signal, it detects that the input supply voltage has been below

the VANA_UVLOlevel (or the host has requested reset with the RESET(SW_RESET) bit), and the registers are

reset to the default values.

7.3.11 OTP Error Correction

LP87702 supports the OTP bit error detection and 1-bit error correction per five registers. The ECC_STATUS

register bit SED is set if a single bit error was detected and corrected. DED bit is set in case two bit errors have

been detected in any bank of five registers.

7.3.12 Operation of GPO Signals

The LP87702 device supports up to 3 general purpose output (GPO) signals. The GPO1 signal is multiplexed

with the PG1 signal and GPO2 signal is multiplexed with the CLKIN and WD_DIS signals. The selection between

signal use are set with the GPO1_SEL and GPO2_SEL bits in the GPO_CONTROL_2 register.

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The type of output, either push-pull (with V_(VANA)level) or open drain, are set with the GPO0_OD and

GPO1_PG1_OD bits in the GPO_CONTROL_1 register and the GPO2_OD bit in the GPO_CONTROL_2

register.

The logic level of the GPOx pins are is set by the GPO0_OUT and GPO1_OUT bits in the GPO_CONTROL_1

register and the GPO2_OUT bit in the GPO_CONTROL_2 register.

The control of the GPOs can be included to start-up and shutdown sequences. The GPO control for a sequence

with ENx pin is selected by the GPOx_EN_PIN_CTRL bits. The delays during start-up and shutdown are set by

bits in the GPOx_DELAY registers.

7.3.13 Digital Signal Filtering

The digital signals have a debounce filtering. The signal or supply is sampled with a clock signal and a counter.

This results as an accuracy of one clock period for the debounce window.

Table 7-7. Digital Signal Filtering

RISING EDGE

FALLING EDGE

LENGTH

EVENT

SIGNAL/SUPPLY

LENGTH

Enable or Disable for BUCKx,

BOOST, or GPOx

ENx

3 µs⁽¹⁾

VANA undervoltage lockout

VANA overvoltage

VANA

Immediate (VANA voltage rising)

Immediate (VANA voltage falling)

1 µs (VANA voltage rising)

1 µs (VANA voltage falling)

Thermal warning

TDIE_WARN_INT

20 µs

64 µs

20 µs

64 µs

Thermal shutdown

TDIE_SD_INT

Current limit, BUCKx

Current limit, BOOST

FB_B0, FB_B1,

VOUT_BST

Overload

1 ms

6 µs

N/V

6 µs

PGx pin and power-good

interrupt (voltage monitoring)

PG0, PG1 / FB_B0, FB_B1

PGx pin and power-good

interrupt (voltage monitoring)

PG0, PG1 / VOUT_BST,

VANA, VMON1, VMON2

15 µs

(1) No glitch filtering; only synchronization.

7.4 Device Functional Modes

7.4.1 Modes of Operation

SHUTDOWN: The V_(VANA)voltage is below the VANA_UVLOthreshold level or the NRST signal is low. All switch,

reference, control, and bias circuitry of the LP87702 device are turned off.

READ OTP: The main supply voltage (V_(VANA)) is above the VANA_UVLOlevel and the NRST signal is high.

The converters are disabled and the reference and bias circuitry of the LP87702 are enabled.

The OTP bits are loaded to the registers. I2C access is not allowed during OTP read. Section

7.3.8 shows how this also applies to the watchdog.

STANDBY:

The main supply voltage (V_(VANA)) is above the VANA_UVLOlevel and the NRST signal is high.

All registers can be read or written by the host processor through the system serial interface.

Watchdog is active and the WDI input is expected to toggle to avoid watchdog expiration. The

converters are disabled and the LP87702's reference, control, and bias circuitry are enabled.

The converters can be enabled if needed.

ACTIVE:

The main supply voltage (V_(VANA)) is above the VANA_UVLOlevel and the NRST signal is high. At

least one converter is enabled. All registers can be read or written by the host processor through

the system's serial interface. Watchdog is active and the WDI input is expected to toggle to avoid

watchdog expiration.

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Figure 7-14 shows the operating modes and transitions between the modes. See Section 7.3.8 for the window

watchdog detailed operation.

SHUTDOWN

NRST low OR

< VANA_UVLO

V

VANA

NRST high AND

> VANA_UVLO

V

VANA

FROM ANY STATE

EXCEPT SHUTDOWN

READ

OTP

REG

RESET

STANDBY

2

I C RESET

CONVERTER

ENABLED

CONVERTER(S)

DISABLED

ACTIVE

Figure 7-14. Device Operation Modes.

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7.5 Programming

7.5.1 I²C-Compatible Interface

The I²C-compatible synchronous serial interface provides access to the programmable functions and registers

on the device. This protocol uses a two-wire interface for bidirectional communications between the ICs

connected to the bus. The two interface lines are the serial data line (SDA) and the serial clock line (SCL).

Every device on the bus is assigned a unique address and acts as either a master or a slave depending on

whether it generates or receives the serial clock SCL. The SCL and SDA lines should each have a pull-up

resistor placed somewhere on the line and remain HIGH even when the bus is idle. The LP87702 supports

standard mode (100 kHz), fast mode (400 kHz), fast mode plus (1 MHz), and high-speed mode (3.4 MHz).

7.5.1.1 Data Validity

The data on the SDA line must be stable during the HIGH period of the clock signal (SCL). In other words, the

state of the data line can only be changed when clock signal is LOW.

SCL

SDA

data

change

allowed

data

change

allowed

data

change

allowed

data

valid

data

valid

Figure 7-15. Data Validity Diagram

7.5.1.2 Start and Stop Conditions

The LP87702 is controlled through an I²C-compatible interface. START and STOP conditions classify the

beginning and end of the I²C session. A START condition is defined as SDA transitions from HIGH to LOW

while SCL is HIGH. A STOP condition is defined as SDA transition from LOW to HIGH while SCL is HIGH. The

I²C master always generates the START and STOP conditions.

SDA

SCL

S

P

START

STOP

Condition

Figure 7-16. Start and Stop Sequences

The I²C bus is considered busy after a START condition and free after a STOP condition. The I²C master can

generate repeated START conditions during data transmission. A START and a repeated START condition are

equivalent function-wise. The data on SDA must be stable during the HIGH period of the clock signal (SCL). In

other words, the state of SDA can only be changed when SCL is LOW. Figure 7-17 shows the SDA and SCL

signal timing for the I²C-Compatible Bus.

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t_BUF

SDA

t_HD;STA

t_rCL

t_fDA

t_rDA

t_SP

t_LOW

t_fCL

SCL

t_HD;STA

t_SU;STA

t_SU;STO

t_HIGH

t_HD;DAT

S

START

t_SU;DAT

S

RS

P

REPEATED

START

STOP

START

Figure 7-17. I²C-Compatible Timing

7.5.1.3 Transferring Data

Every byte put on the SDA line must be eight bits long, with the most significant bit (MSB) being transferred first.

Each byte of data has to be followed by an acknowledge bit. The acknowledge related clock pulse is generated

by the master. The master releases the SDA line (HIGH) during the acknowledge clock pulse. The LP87702

pulls down the SDA line during the 9th clock pulse, signifying an acknowledge. The LP87702 generates an

acknowledge after each byte has been received.

There is one exception to the acknowledge after every byte rule. When the master is the receiver, it must

indicate to the transmitter an end of data by not acknowledging (negative acknowledge) the last byte clocked out

of the slave. This negative acknowledge still includes the acknowledge clock pulse (generated by the master),

but the SDA line is not pulled down.

Note

If the V_(VANA)voltage is below the VANA_UVLOthreshold level during I²C communication, the LP87702

device does not drive the SDA line. The ACK signal and data transfer to the master is disabled at that

time.

The bus master sends a chip address after the START condition. This address is seven bits long followed by an

eighth bit which is a data direction bit (READ or WRITE). A 0 indicates a WRITE and a 1 indicates a READ for

the eighth bit. The second byte selects the register to which the data is written. The third byte contains data to

write to the selected register.

ACK from slave

START MSB Chip Address LSB

W

ACK MSB Register Address LSB ACK

MSB Data LSB

ACK STOP

SCL

SDA

START

id = 0x60

W

ACK

address = 0x40

ACK

address 0x40 data

ACK STOP

Figure 7-18. Write Cycle (w = write; SDA = 0), id = Device Address = 60Hex for LP87702

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ACK from slave

ACK from slave REPEATED START

ACK from slave Data from slave NACK from master

START MSB Chip Address LSB

W

MSB Register Address LSB

RS

MSB Chip Address LSB

R

MSB Data LSB

STOP

SCL

SDA

START

ACK

NACK

STOP

id = 0x60

W

address = 0x3F

RS

id = 0x60

R

address 0x3F data

A WRITE function must precede the READ function as shown above when the READ function is accomplished.

Figure 7-19. Read Cycle (r = read; SDA = 1), id = Device Address = 60Hex for LP87702

7.5.1.4 I²C-Compatible Chip Address

The device address for the LP87702 is 0x60. After the START condition, the I²C master sends the 7-bit address

followed by an eighth bit, read or write (R/W). R/W = 0 indicates a WRITE and R/W = 1 indicates a READ. The

second byte following the device address selects the register address to which the data will be written. The third

byte contains the data for the selected register.

MSB

LSB

1

Bit 7

1

Bit 6

0

Bit 5

0

Bit 4

0

Bit 3

0

Bit 2

0

Bit 1

R/W

Bit 0

I²C Slave Address (chip address)

A. Here device address is 1100000Bin = 60Hex.

Figure 7-20. Device Address

7.5.1.5 Auto Increment Feature

The auto-increment feature allows writing several consecutive registers within one transmission. The internal

address index counter increments by one and the next register will be written every time an 8-bit word is sent

to the LP87702. Table 7-8 below shows writing sequence to two consecutive registers. Note: the auto increment

feature does not work for read.

Table 7-8. Auto-Increment Example

MASTER START DEVICE

WRITE

REGISTER

ADDRESS

DATA

STOP

ACTION

ADDRESS =

60H

LP87702

ACK

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7.6 Register Maps

7.6.1 Register Descriptions

The LP87702 is controlled by a set of registers through the system serial interface port. This register map

describes the default values for the bits which are not read from OTP memory. The asterisk (*) marking indicates

the register bits which are updated from the OTP memory during the READ OTP state. OTP values for each

orderable part number are described in a separate technical reference manual TRM.

7.6.1.1 LP8770_map Registers

Table 7-9 lists the memory-mapped registers for the LP8770_map registers. All register offset addresses not

listed in Table 7-9 should be considered as reserved locations and the register contents should not be modified.

Table 7-9. LP8770_MAP Registers

Offset

0h

Acronym

Register Name

Section

DEV_REV

Section 7.6.1.1.1

Section 7.6.1.1.2

Section 7.6.1.1.3

Section 7.6.1.1.4

Section 7.6.1.1.5

Section 7.6.1.1.6

Section 7.6.1.1.7

Section 7.6.1.1.8

Section 7.6.1.1.9

Section 7.6.1.1.10

Section 7.6.1.1.11

Section 7.6.1.1.12

Section 7.6.1.1.13

Section 7.6.1.1.14

Section 7.6.1.1.15

Section 7.6.1.1.16

Section 7.6.1.1.17

Section 7.6.1.1.18

Section 7.6.1.1.19

Section 7.6.1.1.20

Section 7.6.1.1.21

Section 7.6.1.1.22

Section 7.6.1.1.23

Section 7.6.1.1.24

Section 7.6.1.1.25

Section 7.6.1.1.26

Section 7.6.1.1.27

Section 7.6.1.1.28

Section 7.6.1.1.29

Section 7.6.1.1.30

Section 7.6.1.1.31

Section 7.6.1.1.32

Section 7.6.1.1.33

Section 7.6.1.1.34

Section 7.6.1.1.35

1h

OTP_CODE

2h

BUCK0_CTRL_1

BUCK0_CTRL_2

BUCK1_CTRL_1

BUCK1_CTRL_2

BUCK0_VOUT

BUCK1_VOUT

BOOST_CTRL

BUCK0_DELAY

BUCK1_DELAY

BOOST_DELAY

GPO0_DELAY

GPO1_DELAY

GPO2_DELAY

GPO_CONTROL_1

GPO_CONTROL_2

CONFIG

3h

4h

5h

6h

7h

8h

9h

Ah

Bh

Ch

Dh

Eh

Fh

10h

11h

12h

13h

14h

15h

16h

17h

18h

19h

1Ah

1Bh

1Ch

1Dh

1Eh

1Fh

20h

21h

22h

PLL_CTRL

PGOOD_CTRL

PGOOD_LEVEL_1

PGOOD_LEVEL_2

PGOOD_LEVEL_3

PG_CTRL

PG0_CTRL

PG0_FAULT

PG1_CTRL

PG1_FAULT

WD_CTRL_1

WD_CTRL_2

WD_STATUS

RESET

INT_TOP_1

INT_TOP_2

INT_BUCK

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Table 7-9. LP8770_MAP Registers (continued)

Offset

23h

24h

25h

26h

27h

28h

29h

2Ah

2Bh

2Ch

2Dh

2Eh

2Fh

30h

31h

32h

33h

34h

35h

Acronym

Register Name

Section

INT_BOOST

Section 7.6.1.1.36

Section 7.6.1.1.37

Section 7.6.1.1.38

Section 7.6.1.1.39

Section 7.6.1.1.40

Section 7.6.1.1.41

Section 7.6.1.1.42

Section 7.6.1.1.43

Section 7.6.1.1.44

Section 7.6.1.1.45

Section 7.6.1.1.46

Section 7.6.1.1.47

Section 7.6.1.1.48

Section 7.6.1.1.49

Section 7.6.1.1.50

Section 7.6.1.1.51

Section 7.6.1.1.52

Section 7.6.1.1.53

Section 7.6.1.1.54

INT_DIAG

TOP_STATUS

BUCK_STATUS

BOOST_STATUS

DIAG_STATUS

TOP_MASK_1

TOP_MASK_2

BUCK_MASK

BOOST_MASK

DIAG_MASK

SEL_I_LOAD

I_LOAD_2

I_LOAD_1

FREQ_SEL

BOOST_ILIM_CTRL

ECC_STATUS

WD_DIS_CTRL_CODE

WD_DIS_CONTROL

Complex bit access types are encoded to fit into small table cells. Table 7-10 shows the codes that are used for

access types in this section.

Table 7-10. LP8770_map Access Type Codes

Access Type

Read Type

R

Code

Description

R

Read

Write Type

W

Write

Reset or Default Value

-n

Value after reset or the default

value

Register Array Variables

i,j,k,l,m,n

When these variables are used in

a register name, an offset, or an

address, they refer to the value of

a register array where the register

is part of a group of repeating

registers. The register groups

form a hierarchical structure and

the array is represented with a

formula.

y

When this variable is used in a

register name, an offset, or an

address it refers to the value of

a register array.

7.6.1.1.1 DEV_REV Register (Offset = 0h) [reset = 0h]

DEV_REV is shown in Figure 7-19 and described in Table 7-11.

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Return to Table 7-9.

Figure 7-19. DEV_REV Register

7

6

5

4

3

2

1

0

RESERVED

R-0h

DEVICE_ID

R-0h

Table 7-11. DEV_REV Register Field Descriptions

Bit

7-6

5-3

Field

Type

Reset

Description

RESERVED

DEVICE_ID

R

0h

R

0h

Device specific ID code.

(Default from OTP memory)

7.6.1.1.2 OTP_CODE Register (Offset = 1h) [reset = 0h]

OTP_CODE is shown in Figure 7-20 and described in Table 7-12.

Return to Table 7-9.

Figure 7-20. OTP_CODE Register

7

6

5

4

3

2

1

0

OTP_ID

R-0h

OTP_REV

R-0h

Table 7-12. OTP_CODE Register Field Descriptions

Bit

Field

Type

Reset

Description

7-2

OTP_ID

R

0h

Identification Code of the OTP EPROM.

(Default from OTP memory)

1-0

OTP_REV

R

0h

Version number of the OTP ID.

(Default from OTP memory)

7.6.1.1.3 BUCK0_CTRL_1 Register (Offset = 2h) [reset = 8h]

BUCK0_CTRL_1 is shown in Figure 7-21 and described in Table 7-13.

Return to Table 7-9.

Figure 7-21. BUCK0_CTRL_1 Register

7

6

5

4

3

2

1

0

BUCK0_EN

RESERVED

R/W-0h

BUCK0_FPWM BUCK0_RDIS_

EN

BUCK0_EN_PIN_CTRL

R/W-0h

R/W-1h

R/W-0h

Table 7-13. BUCK0_CTRL_1 Register Field Descriptions

Bit

Field

Type

R/W

Reset

Description

7-6

4

RESERVED

0h

BUCK0_FPWM

0h

Forces the BUCK0 converter to operate in PWM mode:

0 – Automatic transitions between PFM and PWM modes (AUTO

mode).

1 – Forced to PWM operation.

(Default from OTP memory)

3

BUCK0_RDIS_EN

R/W

1h

Enable output discharge resistor when BUCK0 is disabled:

0 – Discharge resistor disabled

1 – Discharge resistor enabled.

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Table 7-13. BUCK0_CTRL_1 Register Field Descriptions (continued)

Bit

Field

Type

Reset

Description

2-1

BUCK0_EN_PIN_CTRL

R/W

0h

Enable or disable control for BUCK0:

0x0 – only BUCK0_EN bit controls BUCK0

0x1 – BUCK0_EN bit AND EN1 pin control BUCK0

0x2 – BUCK0_EN bit AND EN2 pin control BUCK0

0x3 – BUCK0_EN bit AND EN3 pin control BUCK0

(Default from OTP memory)

0

BUCK0_EN

R/W

0h

Enable BUCK0 converter:

0 – BUCK0 converter is disabled

1 – BUCK0 converter is enabled.

(Default from OTP memory)

7.6.1.1.4 BUCK0_CTRL_2 Register (Offset = 3h) [reset = 1Ah]

BUCK0_CTRL_2 is shown in Figure 7-22 and described in Table 7-14.

Return to Table 7-9.

Figure 7-22. BUCK0_CTRL_2 Register

7

6

5

4

3

2

1

0

RESERVED

R/W-0h

BUCK0_ILIM

R/W-3h

BUCK0_SLEW_RATE

R/W-2h

Table 7-14. BUCK0_CTRL_2 Register Field Descriptions

Bit

Field

Type

R/W

Reset

Description

7-6

5-3

RESERVED

BUCK0_ILIM

0h

3h

Sets the switch peak current limit of BUCK0. Can be programmed at

any time during operation:

0x0 – 1.5 A

0x1 – 2.0 A

0x2 – 2.5 A

0x3 – 3.0 A

0x4 – 3.5 A

0x5 – 4.0 A

0x6 – 4.5 A

0x7 – Reserved

(Default from OTP memory)

2-0

BUCK0_SLEW_RATE

R/W

2h

Sets the output voltage slew rate for BUCK0 converter (rising and

falling edges):

0x0 – Reserved

0x1 – Reserved

0x2 – 10 mV/μs

0x3 – 7.5 mV/μs

0x4 – 3.8 mV/μs

0x5 – 1.9 mV/μs

0x6 – 0.94 mV/μs

0x7 – 0.47 mV/μs

(Default from OTP memory)

7.6.1.1.5 BUCK1_CTRL_1 Register (Offset = 4h) [reset = 8h]

BUCK1_CTRL_1 is shown in Figure 7-23 and described in Table 7-15.

Return to Table 7-9.

Figure 7-23. BUCK1_CTRL_1 Register

7

6

5

4

3

2

1

0

RESERVED

BUCK1_FPWM BUCK1_RDIS_

EN

BUCK1_EN_PIN_CTRL

BUCK1_EN

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Figure 7-23. BUCK1_CTRL_1 Register (continued)

R/W-0h

R/W-1h

R/W-0h

Table 7-15. BUCK1_CTRL_1 Register Field Descriptions

Bit

7-5

4

Field

Type

R/W

Reset

Description

RESERVED

0h

BUCK1_FPWM

0h

Forces the BUCK1 converter to operate in PWM mode:

0 – Automatic transitions between PFM and PWM modes (AUTO

mode).

1 – Forced to PWM operation.

(Default from OTP memory)

3

BUCK1_RDIS_EN

R/W

1h

0h

Enable output discharge resistor when BUCK1 is disabled:

0 – Discharge resistor disabled

1 – Discharge resistor enabled.

2-1

BUCK1_EN_PIN_CTRL

Enable or disable control for BUCK1:

0x0 – only BUCK1_EN bit controls BUCK1

0x1 – BUCK1_EN bit AND EN1 pin control BUCK1

0x2 – BUCK1_EN bit AND EN2 pin control BUCK1

0x3 – BUCK1_EN bit AND EN3 pin control BUCK1

(Default from OTP memory)

0

BUCK1_EN

R/W

0h

Enable BUCK1 converter:

0 – BUCK1 converter is disabled

1 – BUCK1 converter is enabled.

(Default from OTP memory)

7.6.1.1.6 BUCK1_CTRL_2 Register (Offset = 5h) [reset = 1Ah]

BUCK1_CTRL_2 is shown in Figure 7-24 and described in Table 7-16.

Return to Table 7-9.

Figure 7-24. BUCK1_CTRL_2 Register

7

6

5

4

3

2

1

0

RESERVED

R/W-0h

BUCK1_ILIM

R/W-3h

BUCK1_SLEW_RATE

R/W-2h

Table 7-16. BUCK1_CTRL_2 Register Field Descriptions

Bit

Field

Type

R/W

Reset

Description

7-6

5-3

RESERVED

BUCK1_ILIM

0h

3h

Sets the switch peak current limit of BUCK1. Can be programmed at

any time during operation:

0x0 – 1.5 A

0x1 – 2.0 A

0x2 – 2.5 A

0x3 – 3.0 A

0x4 – 3.5 A

0x5 – 4.0 A

0x6 – 4.5 A

0x7 – Reserved

(Default from OTP memory)

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Table 7-16. BUCK1_CTRL_2 Register Field Descriptions (continued)

Bit

Field

Type

Reset

Description

2-0

BUCK1_SLEW_RATE

R/W

2h

Sets the output voltage slew rate for BUCK1 converter (rising and

falling edges):

0x0 – Reserved

0x1 – Reserved

0x2 – 10 mV/μs

0x3 – 7.5 mV/μs

0x4 – 3.8 mV/μs

0x5 – 1.9 mV/μs

0x6 – 0.94 mV/μs

0x7 – 0.47 mV/μs

(Default from OTP memory)

7.6.1.1.7 BUCK0_VOUT Register (Offset = 6h) [reset = 0h]

BUCK0_VOUT is shown in Figure 7-25 and described in Table 7-17.

Return to Table 7-9.

Figure 7-25. BUCK0_VOUT Register

7

6

5

4

3

2

1

0

BUCK0_VSET

R/W-0h

Table 7-17. BUCK0_VOUT Register Field Descriptions

Bit

7-0

Field

BUCK0_VSET

Type

Reset

Description

R/W

0h

Output voltage of BUCK0 converter:

0x00 ... 0x13, Reserved, DO NOT USE

0.7 V – 0.73 V, 10 mV steps

0x14 – 0.7 V

...

0x17 – 0.73 V

0.73 V – 1.4 V, 5 mV steps

0x18 – 0.735 V

...

0x9D – 1.4 V

1.4 V – 3.36 V, 20 mV steps

0x9E – 1.42 V

...

0xFF – 3.36 V

(Default from OTP memory)

7.6.1.1.8 BUCK1_VOUT Register (Offset = 7h) [reset = 0h]

BUCK1_VOUT is shown in Figure 7-26 and described in Table 7-18.

Return to Table 7-9.

Figure 7-26. BUCK1_VOUT Register

7

6

5

4

3

2

1

0

BUCK1_VSET

R/W-0h

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Table 7-18. BUCK1_VOUT Register Field Descriptions

Bit

Field

Type

Reset

Description

7-0

BUCK1_VSET

R/W

0h

Output voltage of BUCK1 converter

0x00 ... 0x13, Reserved, DO NOT USE

0.7 V – 0.73 V, 10 mV steps

0x14 – 0.7 V

...

0x17 – 0.73 V

0.73 V – 1.4 V, 5 mV steps

0x18 – 0.735 V

...

0x9D – 1.4 V

1.4 V – 3.36 V, 20 mV steps

0x9E – 1.42 V

...

0xFF – 3.36 V

(Default from OTP memory)

7.6.1.1.9 BOOST_CTRL Register (Offset = 8h) [reset = 8h]

BOOST_CTRL is shown in Figure 7-27 and described in Table 7-19.

Return to Table 7-9.

Figure 7-27. BOOST_CTRL Register

7

6

5

4

3

2

1

0

BOOST_VSET

R/W-0h

RESERVED

BOOST_RDIS_

EN

BOOST_EN_PIN_CTRL

R/W-0h

BOOST_EN

R/W-0h

R/W-1h

R/W-0h

Table 7-19. BOOST_CTRL Register Field Descriptions

Bit

Field

Type

Reset

Description

7-6

BOOST_VSET

R/W

0h

Output voltage of Boost:

0x0 – 4.9 V

0x1 – 5.0 V

0x2 – 5.1 V

0x3 – 5.2 V

(Default from OTP memory)

5

4

3

RESERVED

R/W

0h

1h

RESERVED

BOOST_RDIS_EN

Enable output discharge resistor when BOOST is disabled:

0 – Discharge resistor disabled

1 – Discharge resistor enabled.

2-1

BOOST_EN_PIN_CTRL

R/W

0h

Enable or disable control for Boost:

0x0 – only BOOST_EN bit controls Boost

0x1 – BOOST_EN bit AND EN1 pin control Boost

0x2 – BOOST_EN bit AND EN2 pin control Boost

0x3 – BOOST_EN bit AND EN3 pin control Boost

(Default from OTP memory)

0

BOOST_EN

R/W

0h

Enable Boost converter:

0 – Boost converter is disabled

1 – Boost converter is enabled.

(Default from OTP memory)

7.6.1.1.10 BUCK0_DELAY Register (Offset = 9h) [reset = 0h]

BUCK0_DELAY is shown in Figure 7-28 and described in Table 7-20.

Return to Table 7-9.

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Figure 7-28. BUCK0_DELAY Register

7

6

5

4

3

2

1

0

BUCK0_SHUTDOWN_DELAY

R/W-0h

BUCK0_STARTUP_DELAY

R/W-0h

Table 7-20. BUCK0_DELAY Register Field Descriptions

Bit

Field

Type

Reset

Description

7-4

BUCK0_SHUTDOWN_DE R/W

LAY

0h

Shutdown delay of BUCK0 from falling edge of control signal:

0000 – 0 ms

0001 – 0.5 ms (1 ms if CONFIG(STARTUP_DELAY_SEL)=1)

...

1111 – 7.5 ms (15 ms if CONFIG(STARTUP_DELAY_SEL)=1)

(Default from OTP memory)

3-0

BUCK0_STARTUP_DELA R/W

Y

0h

Startup delay of BUCK0 from rising edge of control signal:

0000 – 0 ms

0001 – 0.5 ms (1 ms if CONFIG(STARTUP_DELAY_SEL)=1)

...

1111 – 7.5 ms (15 ms if CONFIG(STARTUP_DELAY_SEL)=1)

(Default from OTP memory)

7.6.1.1.11 BUCK1_DELAY Register (Offset = Ah) [reset = 0h]

BUCK1_DELAY is shown in Figure 7-29 and described in Table 7-21.

Return to Table 7-9.

Figure 7-29. BUCK1_DELAY Register

7

6

5

4

3

2

1

0

BUCK1_SHUTDOWN_DELAY

R/W-0h

BUCK1_STARTUP_DELAY

R/W-0h

Table 7-21. BUCK1_DELAY Register Field Descriptions

Bit

Field

Type

Reset

Description

7-4

BUCK1_SHUTDOWN_DE R/W

LAY

0h

Shutdown delay of BUCK1 from falling edge of control signal:

0000 – 0 ms

0001 – 0.5 ms (1 ms if CONFIG(STARTUP_DELAY_SEL)=1)

...

1111 – 7.5 ms (15 ms if CONFIG(STARTUP_DELAY_SEL)=1)

(Default from OTP memory)

3-0

BUCK1_STARTUP_DELA R/W

Y

0h

Startup delay of BUCK1 from rising edge of control signal:

0000 – 0 ms

0001 – 0.5 ms (1 ms if CONFIG(STARTUP_DELAY_SEL)=1)

...

1111 – 7.5 ms (15 ms if CONFIG(STARTUP_DELAY_SEL)=1)

(Default from OTP memory)

7.6.1.1.12 BOOST_DELAY Register (Offset = Bh) [reset = 0h]

BOOST_DELAY is shown in Figure 7-30 and described in Table 7-22.

Return to Table 7-9.

Figure 7-30. BOOST_DELAY Register

7

6

5

4

3

2

1

0

BOOST_SHUTDOWN_DELAY

R/W-0h

BOOST_STARTUP_DELAY

R/W-0h

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Table 7-22. BOOST_DELAY Register Field Descriptions

Bit

Field

Type

Reset

Description

7-4

BOOST_SHUTDOWN_DE R/W

LAY

0h

Shutdown delay of Boost from falling edge of control signal:

0000 – 0 ms

0001 – 0.5 ms (1 ms if CONFIG(STARTUP_DELAY_SEL)=1)

...

1111 – 7.5 ms (15 ms if CONFIG(STARTUP_DELAY_SEL)=1)

(Default from OTP memory)

3-0

BOOST_STARTUP_DELA R/W

Y

0h

Startup delay of Boost from rising edge of control signal:

0000 – 0 ms

0001 – 0.5 ms (1 ms if CONFIG(STARTUP_DELAY_SEL)=1)

...

1111 – 7.5 ms (15 ms if CONFIG(STARTUP_DELAY_SEL)=1)

(Default from OTP memory)

7.6.1.1.13 GPO0_DELAY Register (Offset = Ch) [reset = 0h]

GPO0_DELAY is shown in Figure 7-31 and described in Table 7-23.

Return to Table 7-9.

Figure 7-31. GPO0_DELAY Register

7

6

5

4

3

2

1

0

GPO0_SHUTDOWN_DELAY

R/W-0h

GPO0_STARTUP_DELAY

R/W-0h

Table 7-23. GPO0_DELAY Register Field Descriptions

Bit

Field

Type

Reset

Description

7-4

GPO0_SHUTDOWN_DEL R/W

AY

0h

Shutdown delay of GPO0 from falling edge of control signal:

0000 – 0 ms

0001 – 0.5 ms (1 ms if CONFIG(STARTUP_DELAY_SEL)=1)

...

1111 – 7.5 ms (15 ms if CONFIG(STARTUP_DELAY_SEL)=1)

(Default from OTP memory)

3-0

GPO0_STARTUP_DELAY R/W

0h

Startup delay of GPO0 from rising edge of control signal:

0000 – 0 ms

0001 – 0.5 ms (1 ms if CONFIG(STARTUP_DELAY_SEL)=1)

...

1111 – 7.5 ms (15 ms if CONFIG(STARTUP_DELAY_SEL)=1)

(Default from OTP memory)

7.6.1.1.14 GPO1_DELAY Register (Offset = Dh) [reset = 0h]

GPO1_DELAY is shown in Figure 7-32 and described in Table 7-24.

Return to Table 7-9.

Figure 7-32. GPO1_DELAY Register

7

6

5

4

3

2

1

0

GPO1_SHUTDOWN_DELAY

R/W-0h

GPO1_STARTUP_DELAY

R/W-0h

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Table 7-24. GPO1_DELAY Register Field Descriptions

Bit

Field

Type

Reset

Description

7-4

GPO1_SHUTDOWN_DEL R/W

AY

0h

Shutdown delay of GPO1 from falling edge of control signal:

0000 – 0 ms

0001 – 0.5 ms (1 ms if CONFIG(STARTUP_DELAY_SEL)=1)

...

1111 – 7.5 ms (15b ms if CONFIG(STARTUP_DELAY_SEL)=1)

(Default from OTP memory)

3-0

GPO1_STARTUP_DELAY R/W

0h

Startup delay of GPO1 from rising edge of control signal:

0000 – 0 ms

0001 – 0.5 ms (1 ms if CONFIG(STARTUP_DELAY_SEL)=1)

...

1111 – 7.5 ms (15 ms if CONFIG(STARTUP_DELAY_SEL)=1)

(Default from OTP memory)

7.6.1.1.15 GPO2_DELAY Register (Offset = Eh) [reset = 0h]

GPO2_DELAY is shown in Figure 7-33 and described in Table 7-25.

Return to Table 7-9.

Figure 7-33. GPO2_DELAY Register

7

6

5

4

3

2

1

0

GPO2_SHUTDOWN_DELAY

R/W-0h

GPO2_STARTUP_DELAY

R/W-0h

Table 7-25. GPO2_DELAY Register Field Descriptions

Bit

Field

Type

Reset

Description

7-4

GPO2_SHUTDOWN_DEL R/W

AY

0h

Shutdown delay of GPO2 from falling edge of control signal:

0000 – 0 ms

0001 – 0.5 ms (1 ms if CONFIG(STARTUP_DELAY_SEL)=1)

...

1111 – 7.5 ms (15 ms if CONFIG(STARTUP_DELAY_SEL)=1)

(Default from OTP memory)

3-0

GPO2_STARTUP_DELAY R/W

0h

Startup delay of GPO2 from rising edge of control signal:

0000 – 0 ms

0001 – 0.5 ms (1 ms if CONFIG(STARTUP_DELAY_SEL)=1)

...

1111 – 7.5 ms (15 ms if CONFIG(STARTUP_DELAY_SEL)=1)

(Default from OTP memory)

7.6.1.1.16 GPO_CONTROL_1 Register (Offset = Fh) [reset = AAh]

GPO_CONTROL_1 is shown in Figure 7-34 and described in Table 7-26.

Return to Table 7-9.

Figure 7-34. GPO_CONTROL_1 Register

7

6

5

4

3

2

1

0

GPO1_PG1_O

D

GPO1_EN_PIN_CTRL

R/W-1h

GPO1_OUT

GPO0_OD

GPO0_EN_PIN_CTRL

R/W-1h

GPO0_OUT

R/W-1h

R/W-0h

R/W-1h

R/W-0h

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Table 7-26. GPO_CONTROL_1 Register Field Descriptions

Bit

Field

Type

Reset

Description

7

GPO1_PG1_OD

R/W

1h

GPO1/PG1 signal type:

0 – Push-pull output (VANA level)

1 – Open-drain output

(Default from OTP memory)

6-5

GPO1_EN_PIN_CTRL

R/W

1h

Control for GPO1 output:

0x0 – only GPO1_OUT bit controls GPO1

0x1 – GPO1_OUT bit AND EN1 pin control GPO1

0x2 – GPO1_OUT bit AND EN2 pin control GPO1

0x3 – GPO1_OUT bit AND EN3 pin control GPO1

(Default from OTP memory)

4

3

GPO1_OUT

R/W

0h

1h

Control for GPO1 signal (when configured to GPO1):

0 – Logic low level

1 – Logic high level

(Default from OTP memory)

GPO0_OD

GPO0 signal type:

0 – Push-pull output (VANA level)

1 – Open-drain output

(Default from OTP memory)

2-1

GPO0_EN_PIN_CTRL

Control for GPO0 output:

0x0 – only GPO0_OUT bit controls GPO0

0x1 – GPO0_OUT bit AND EN1 pin control GPO0

0x2 – GPO0_OUT bit AND EN2 pin control GPO0

0x3 – GPO0_OUT bit AND EN3 pin control GPO0

(Default from OTP memory)

0

GPO0_OUT

R/W

0h

Control for GPO0 signal:

0 – Logic low level

1 – Logic high level

(Default from OTP memory)

7.6.1.1.17 GPO_CONTROL_2 Register (Offset = 10h) [reset = Ah]

GPO_CONTROL_2 is shown in Figure 7-35 and described in Table 7-27.

Return to Table 7-9.

Figure 7-35. GPO_CONTROL_2 Register

7

6

5

4

3

2

1

0

RESERVED

R/W-0h

GPO2_SEL

R/W-0h

GPO1_SEL

R/W-0h

GPO2_OD

R/W-1h

GPO2_EN_PIN_CTRL

R/W-1h

GPO2_OUT

R/W-0h

Table 7-27. GPO_CONTROL_2 Register Field Descriptions

Bit

Field

Type

R/W

Reset

Description

7-6

5

RESERVED

GPO2_SEL

0h

CLKIN/GPO2 pin function:

0 – CLKIN

1 – GPO2

(Default from OTP memory)

4

3

GPO1_SEL

GPO2_OD

R/W

0h

1h

PG1/GPO1 pin function:

0 – PG1

1 – GPO1

(Default from OTP memory)

GPO2 signal type (when configured to GPO2):

0 – Push-pull output (VANA level)

1 – Open-drain output

(Default from OTP memory)

54

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Table 7-27. GPO_CONTROL_2 Register Field Descriptions (continued)

Bit

Field

Type

Reset

Description

2-1

GPO2_EN_PIN_CTRL

R/W

1h

Control for GPO2 output:

0x0 – only GPO2_OUT bit controls GPO2

0x1 – GPO2_OUT bit AND EN1 pin control GPO2

0x2 – GPO2_OUT bit AND EN2 pin control GPO2

0x3 – GPO2_OUT bit AND EN3 pin control GPO2

(Default from OTP memory)

0

GPO2_OUT

R/W

0h

Control for GPO2 signal (when configured to GPO2):

0 – Logic low level

1 – Logic high level

(Default from OTP memory)

7.6.1.1.18 CONFIG Register (Offset = 11h) [reset = 3Ch]

CONFIG is shown in Figure 7-36 and described in Table 7-28.

Return to Table 7-9.

Figure 7-36. CONFIG Register

7

6

5

4

3

2

1

0

STARTUP_DEL SHUTDOWN_D

CLKIN_PD

EN3_PD

EN2_PD

EN1_PD

TDIE_WARN_L EN_SPREAD_

AY_SEL

ELAY_SEL

EVEL

SPEC

R/W-0h

R/W-1h

R/W-0h

Table 7-28. CONFIG Register Field Descriptions

Bit

Field

Type

Reset

Description

7

STARTUP_DELAY_SEL

R/W

0h

Startup delays from control signal:

0 – 0 ms – 7.5 ms with 0.5ms steps

1 – 0ms – 15ms with 1ms steps

(Default from OTP memory)

6

5

4

3

2

1

0

SHUTDOWN_DELAY_SE R/W

L

0h

1h

0h

Shutdown delays from from signal:

0 – 0ms – 7.5ms with 0.5ms steps

1 – 0ms – 15ms with 1ms steps

(Default from OTP memory)

CLKIN_PD

R/W

Selects the pull down resistor on the CLKIN input pin.

0 – Pull-down resistor is disabled.

1 – Pull-down resistor is enabled.

(Default from OTP memory)

EN3_PD

Selects the pull down resistor on the EN3 pin:

0 – Pull-down resistor is disabled

1 – Pull-down resistor is enabled

(Default from OTP memory)

EN2_PD

Selects the pull down resistor on the EN2 pin:

0 – Pull-down resistor is disabled

1 – Pull-down resistor is enabled

(Default from OTP memory)

EN1_PD

Selects the pull down resistor on the EN1 pin:

0 – Pull-down resistor is disabled

1 – Pull-down resistor is enabled

(Default from OTP memory)

TDIE_WARN_LEVEL

EN_SPREAD_SPEC

Thermal warning threshold level.

0 – 125°C

1 – 140°C.

(Default from OTP memory)

Enable spread spectrum feature for Buck and Boost converters.

0 – Disabled

1 – Enabled

(Default from OTP memory)

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7.6.1.1.19 PLL_CTRL Register (Offset = 12h) [reset = 2h]

PLL_CTRL is shown in Figure 7-37 and described in Table 7-29.

Return to Table 7-9.

Figure 7-37. PLL_CTRL Register

7

6

5

4

3

2

1

0

RESERVED

R/W-0h

EN_PLL

R/W-0h

EN_FRAC_DIV

R/W-0h

EXT_CLK_FREQ

R/W-2h

Table 7-29. PLL_CTRL Register Field Descriptions

Bit

7

Field

RESERVED

Type

R/W

Reset

Description

0h

6

EN_PLL

0h

Selection of external clock and PLL operation:

0 – Forced to internal RC oscillator. PLL disabled.

1 – PLL is enabled in STANDBY and ACTIVE modes. Automatic

external clock use when available, interrupt generated if external

clock appears or disappears.

(Default from OTP memory)

5

EN_FRAC_DIV

R/W

0h

2h

This bit must be set to '0'.

4-0

EXT_CLK_FREQ

Frequency of the external clock (CLKIN):

0x00 – 1 MHz

0x01 – 2 MHz

0x02 – 3 MHz

...

0x16 – 23 MHz

0x17 – 24 MHz

0x18...0x1F – Reserved

See electrical specification for input clock frequency tolerance.

(Default from OTP memory) Note: To ensure proper operation of

PLL, EXT_CLK_FREQ value must not be changed when PLL is

enabled.

7.6.1.1.20 PGOOD_CTRL Register (Offset = 13h) [reset = 0h]

PGOOD_CTRL is shown in Figure 7-38 and described in Table 7-30.

Return to Table 7-9.

Figure 7-38. PGOOD_CTRL Register

7

6

5

4

3

2

1

0

RESERVED

PGOOD_WIND EN_PGOOD_V EN_PGOOD_V EN_PGOOD_V EN_PGOOD_B EN_PGOOD_B EN_PGOOD_B

OW

ANA

MON2

MON1

OOST

UCK1

UCK0

R/W-0h

Table 7-30. PGOOD_CTRL Register Field Descriptions

Bit

7

Field

RESERVED

Type

R/W

Reset

Description

0h

6

PGOOD_WINDOW

0h

Voltage monitoring method for PG0 and PG1 signals:

0 - Only undervoltage monitoring.

1 - Overvoltage and undervoltage monitoring.

(Default from OTP memory) Note: Changing this value during

operation may cause interrupt.

5

EN_PGOOD_VANA

R/W

0h

Enable powergood diagnostics for VANA

0 – Disabled

1 – Enabled

(Default from OTP memory) Note: Changing this value during

operation may cause interrupt.

56

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Table 7-30. PGOOD_CTRL Register Field Descriptions (continued)

Bit

Field

Type

Reset

Description

4

EN_PGOOD_VMON2

R/W

0h

Enable powergood diagnostics for VMON2

0 – Disabled

1 – Enabled

(Default from OTP memory) Note: Changing this value during

operation may cause interrupt.

3

2

1

0

EN_PGOOD_VMON1

EN_PGOOD_BOOST

EN_PGOOD_BUCK1

EN_PGOOD_BUCK0

R/W

0h

Enable powergood diagnostics for VMON1

0 – Disabled

1 – Enabled

(Default from OTP memory) Note: Changing this value during

operation may cause interrupt.

Enable powergood diagnostics for Boost

0 – Disabled

1 – Enabled

(Default from OTP memory) Note: Changing this value during

operation may cause interrupt.

Enable powergood diagnostics for Buck1

0 – Disabled

1 – Enabled

(Default from OTP memory) Note: Changing this value during

operation may cause interrupt.

Enable powergood diagnostics for Buck0

0 – Disabled

1 – Enabled

(Default from OTP memory) Note: Changing this value during

operation may cause interrupt.

7.6.1.1.21 PGOOD_LEVEL_1 Register (Offset = 14h) [reset = 0h]

PGOOD_LEVEL_1 is shown in Figure 7-39 and described in Table 7-31.

Return to Table 7-9.

Figure 7-39. PGOOD_LEVEL_1 Register

7

6

5

4

3

2

1

0

RESERVED

R/W-0h

VMON1_WINDOW

R/W-0h

VMON1_THRESHOLD

R/W-0h

Table 7-31. PGOOD_LEVEL_1 Register Field Descriptions

Bit

Field

Type

R/W

Reset

Description

7-5

4-3

RESERVED

0h

VMON1_WINDOW

0h

Overvoltage and undervoltage threshold levels for VMON1:

0x0 – ±2%

0x1 – ±3%

0x2 – ±4%

0x3 – ±6%

(Default from OTP memory)

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Table 7-31. PGOOD_LEVEL_1 Register Field Descriptions (continued)

Bit

Field

Type

Reset

Description

2-0

VMON1_THRESHOLD

R/W

0h

Threshold voltage for VMON1 input:

0x0 – 0.65V (high impedance input, external resistive divider can be

used)

0x1 – 0.80 V

0x2 – 1.00 V

0x3 – 1.10 V

0x4 – 1.20 V

0x5 – 1.30 V

0x6 – 1.80 V

0x7 – 1.80 V

To monitor any other voltage level, select 0x0 and use an external

resistive divider to scale down to 0.65 V. For other than 0x0 VMONx

input is low impedance (internal resistive divider enabled).

(Default from OTP memory)

7.6.1.1.22 PGOOD_LEVEL_2 Register (Offset = 15h) [reset = 0h]

PGOOD_LEVEL_2 is shown in Figure 7-40 and described in Table 7-32.

Return to Table 7-9.

Figure 7-40. PGOOD_LEVEL_2 Register

7

6

5

4

3

2

1

0

VANA_WINDOW

VANA_THRES

HOLD

VMON2_WINDOW

R/W-0h

VMON2_THRESHOLD

R/W-0h

Table 7-32. PGOOD_LEVEL_2 Register Field Descriptions

Bit

Field

Type

Reset

Description

7-6

VANA_WINDOW

R/W

0h

Overvoltage and undervoltage threshold levels for VANA:

0x0 – ±4%

0x1 – ±5%

0x2 – ±10%

0x3 – ±10%

(Default from OTP memory)

5

VANA_THRESHOLD

VMON2_WINDOW

R/W

0h

Threshold voltage for VANA input:

0 – 3.3 V

1 – 5.0 V

(Default from OTP memory)

4-3

Overvoltage and undervoltage threshold levels for VMON2:

0x0 – ±2%

0x1 – ±3%

0x2 – ±4%

0x3 – ±6%

(Default from OTP memory)

2-0

VMON2_THRESHOLD

R/W

0h

Threshold voltage for VMON2 input:

0x0 – 0.65 V (high impedance input, external resistive divider can be

used)

0x1 – 0.80 V

0x2 – 1.00 V

0x3 – 1.10 V

0x4 – 1.20 V

0x5 – 1.30 V

0x6 – 1.80 V

0x7 – 1.80 V

To monitor any other voltage level, select 0x0 and use an external

resistive divider to scale down to 0.65 V. For other than 0x0 VMONx

input is low impedance (internal resistive divider enabled).

(Default from OTP memory)

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7.6.1.1.23 PGOOD_LEVEL_3 Register (Offset = 16h) [reset = 0h]

PGOOD_LEVEL_3 is shown in Figure 7-41 and described in Table 7-33.

Return to Table 7-9.

Figure 7-41. PGOOD_LEVEL_3 Register

7

6

5

4

3

2

1

0

BOOST_WINDOW

R/W-0h

BOOST_THRESHOLD

R/W-0h

BUCK1_WINDOW

R/W-0h

BUCK0_WINDOW

R/W-0h

Table 7-33. PGOOD_LEVEL_3 Register Field Descriptions

Bit

Field

Type

Reset

Description

7-6

BOOST_WINDOW

R/W

0h

Undervoltage or overvoltage threshold levels for Boost:

0x0 – ±2%

0x1 – ±4%

0x2 – ±6%

0x3 – ±8%

(Default from OTP memory)

5-4

3-2

BOOST_THRESHOLD

BUCK1_WINDOW

R/W

0h

(Default from OTP memory)

Overvoltage and undervoltage threshold levels for Buck1:

0x0 – ±30 mV

0x1 – ±50 mV

0x2 – ±70 mV

0x3 – ±90 mV

(Default from OTP memory)

1-0

BUCK0_WINDOW

R/W

0h

Overvoltage and undervoltage threshold levels for Buck0:

0x0 – ±30 mV

0x1 – ±50 mV

0x2 – ±70 mV

0x3 – ±90 mV

(Default from OTP memory)

7.6.1.1.24 PG_CTRL Register (Offset = 17h) [reset = 2h]

PG_CTRL is shown in Figure 7-42 and described in Table 7-34.

Return to Table 7-9.

Figure 7-42. PG_CTRL Register

7

6

5

4

3

2

1

0

PG1_MODE

PGOOD_FAUL

T_GATES_PG1

RESERVED

PG1_POL

PG0_MODE

PGOOD_FAUL

T_GATES_PG0

PG0_OD

PG0_POL

R/W-0h

R/W-1h

R/W-0h

Table 7-34. PG_CTRL Register Field Descriptions

Bit

Field

PG1_MODE

Type

Reset

Description

7

R/W

0h

Operating mode for PG1 signal:

0 – Detecting unusual situations

1 – Showing when requested outputs are not valid.

(Default from OTP memory)

6

5

PGOOD_FAULT_GATES_ R/W

PG1

0h

Type of operation for PG1 signal:

0 – Indicates live status of monitored voltage outputs.

1 – Indicates status of PG1_FAULT register, inactive if at least one of

PG1_FAULT_x bit

is inactive.

(Default from OTP memory)

RESERVED

R/W

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Table 7-34. PG_CTRL Register Field Descriptions (continued)

Bit

Field

Type

Reset

Description

4

PG1_POL

R/W

0h

PG1 signal polarity.

0 – PG1 signal high when monitored outputs are valid

1 – PG1 signal low when monitored outputs are valid

(Default from OTP memory)

3

2

PG0_MODE

R/W

0h

Operating mode for PG0 signal:

0 – Detecting unusual situations

1 – Showing when requested outputs are not valid.

(Default from OTP memory)

PGOOD_FAULT_GATES_ R/W

PG0

Type of operation for PG0 signal:

0 – Indicates live status of monitored voltage outputs.

1 – Indicates status of PG0_FAULT register, inactive if at least one of

PG0_FAULT_x bit

is inactive.

(Default from OTP memory)

1

0

PG0_OD

R/W

1h

0h

PG0 signal type:

0 – Push-pull output (VANA level)

1 – Open-drain output

(Default from OTP memory)

PG0_POL

PG0 signal polarity.

0 – PG0 signal high when monitored outputs are valid

1 – PG0 signal low when monitored outputs are valid

(Default from OTP memory)

7.6.1.1.25 PG0_CTRL Register (Offset = 18h) [reset = 0h]

PG0_CTRL is shown in Figure 7-43 and described in Table 7-35.

Return to Table 7-9.

Figure 7-43. PG0_CTRL Register

7

6

5

4

3

2

1

0

PG0_RISE_DE SEL_PG0_TWA SEL_PG0_VAN SEL_PG0_VM SEL_PG0_VM SEL_PG0_BOO SEL_PG0_BUC SEL_PG0_BUC

LAY

RN

A

ON2

ON1

ST

K1

K0

R/W-0h

Table 7-35. PG0_CTRL Register Field Descriptions

Bit

7

Field

Type

R/W

Reset

Description

PG0_RISE_DELAY

SEL_PG0_TWARN

0h

0 – PG0 rise is not delayed 1 – PG0 rise is delayed 11 ms

6

0h

PG0 control from thermal warning:

0 - Masked

1 – Affecting PGOOD

(Default from OTP memory)

5

4

3

SEL_PG0_VANA

SEL_PG0_VMON2

SEL_PG0_VMON1

R/W

0h

PG0 signal source control from VANA

0 – Masked

1 – Powergood threshold voltage

(Default from OTP memory)

PG0 signal source control from VMON2

0 – Masked

1 – Powergood threshold voltage

(Default from OTP memory)

PG0 signal source control from VMON1

0 – Masked

1 – Powergood threshold voltage

(Default from OTP memory)

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Table 7-35. PG0_CTRL Register Field Descriptions (continued)

Bit

Field

Type

Reset

Description

2

SEL_PG0_BOOST

R/W

0h

PG0 signal source control from Boost

0 – Masked

1 – Powergood threshold voltage

(Default from OTP memory)

1

0

SEL_PG0_BUCK1

SEL_PG0_BUCK0

R/W

0h

PG0 signal source control from Buck1

0 – Masked

1 – Powergood threshold voltage

(Default from OTP memory)

PG0 signal source control from Buck0

0 – Masked

1 – Powergood threshold voltage

(Default from OTP memory)

7.6.1.1.26 PG0_FAULT Register (Offset = 19h) [reset = 0h]

PG0_FAULT is shown in Figure 7-44 and described in Table 7-36.

Return to Table 7-9.

Figure 7-44. PG0_FAULT Register

7

6

5

4

3

2

1

0

RESERVED

PG0_FAULT_T PG0_FAULT_V PG0_FAULT_V PG0_FAULT_V PG0_FAULT_B PG0_FAULT_B PG0_FAULT_B

WARN

ANA

MON2

MON1

OOST

UCK1

UCK0

R-0h

Table 7-36. PG0_FAULT Register Field Descriptions

Bit

7

Field

RESERVED

Type

Reset

Description

R

0h

6

PG0_FAULT_TWARN

PG0_FAULT_VANA

PG0_FAULT_VMON2

PG0_FAULT_VMON1

PG0_FAULT_BOOST

PG0_FAULT_BUCK1

R

0h

Source for PG0 inactive signal:

0 – TWARN has not set PG0 signal inactive.

1 – TWARN is selected for PG0 signal and it has set PG0 signal

inactive. This bit can be cleared by writing '1' to this bit when TWARN

is valid.

5

4

3

2

1

R

0h

Source for PG0 inactive signal:

0 – VANA has not set PG0 signal inactive.

1 –VANA is selected for PG0 signal and it has set PG0 signal

inactive. This bit can be cleared by writing '1' to this bit when VANA

input is valid.

Source for PG0 inactive signal:

0 – VMON2 has not set PG0 signal inactive.

1 – VMON2 is selected for PG0 signal and it has set PG0 signal

inactive. This bit can be cleared by writing '1' to this bit when VMON2

input is valid.

Source for PG0 inactive signal:

0 – VMON1 has not set PG0 signal inactive.

1 – VMON1 is selected for PG0 signal and it has set PG0 signal

inactive. This bit can be cleared by writing '1' to this bit when VMON1

input is valid.

Source for PG0 inactive signal:

0 – Boost has not set PG0 signal inactive.

1 – Boost is selected for PG0 signal and it has set PG0 signal

inactive. This bit can be cleared by writing '1' to this bit when Boost

output is valid.

Source for PG0 inactive signal:

0 – Buck1 has not set PG0 signal inactive.

1 – Buck1 is selected for PG0 signal and it has set PG0 signal

inactive. This bit can be cleared by writing '1' to this bit when Buck1

output is valid.

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Table 7-36. PG0_FAULT Register Field Descriptions (continued)

Bit

Field

Type

Reset

Description

0

PG0_FAULT_BUCK0

R

0h

Source for PG0 inactive signal:

0 – Buck0 has not set PG0 signal inactive.

1 – Buck0 is selected for PG0 signal and it has set PG0 signal

inactive. This bit can be cleared by writing '1' to this bit when Buck0

output is valid.

7.6.1.1.27 PG1_CTRL Register (Offset = 1Ah) [reset = 0h]

PG1_CTRL is shown in Figure 7-45 and described in Table 7-37.

Return to Table 7-9.

Figure 7-45. PG1_CTRL Register

7

6

5

4

3

2

1

0

PG1_RISE_DE SEL_PG1_TWA SEL_PG1_VAN SEL_PG1_VM SEL_PG1_VM SEL_PG1_BOO SEL_PG1_BUC SEL_PG1_BUC

LAY

RN

A

ON2

ON1

ST

K1

K0

R/W-0h

Table 7-37. PG1_CTRL Register Field Descriptions

Bit

7

Field

Type

R/W

Reset

Description

PG1_RISE_DELAY

SEL_PG1_TWARN

0h

0 – PG1 rise is not delayed 1 – PG1 rise is delayed 11ms

6

0h

PG1 control from thermal warning:

0 – Masked

1 – Affecting PGOOD

(Default from OTP memory)

5

4

3

2

1

0

SEL_PG1_VANA

SEL_PG1_VMON2

SEL_PG1_VMON1

SEL_PG1_BOOST

SEL_PG1_BUCK1

SEL_PG1_BUCK0

R/W

0h

PG1 signal source control from VANA

0 – Masked

1 – Powergood threshold voltage

(Default from OTP memory)

PG1 signal source control from VMON2

0 – Masked

1 – Powergood threshold voltage

(Default from OTP memory)

PG1 signal source control from VMON1

0 – Masked

1 – Powergood threshold voltage

(Default from OTP memory)

PG1 signal source control from Boost

0 – Masked

1 – Powergood threshold voltage

(Default from OTP memory)

PG1 signal source control from Buck1

0 – Masked

1 – Powergood threshold voltage

(Default from OTP memory)

PG1 signal source control from Buck0

0 – Masked

1 – Powergood threshold voltage

(Default from OTP memory)

7.6.1.1.28 PG1_FAULT Register (Offset = 1Bh) [reset = 0h]

PG1_FAULT is shown in Figure 7-46 and described in Table 7-38.

Return to Table 7-9.

62

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Figure 7-46. PG1_FAULT Register

7

6

5

4

3

2

1

0

RESERVED

PG1_FAULT_T PG1_FAULT_V PG1_FAULT_V PG1_FAULT_V PG1_FAULT_B PG1_FAULT_B PG1_FAULT_B

WARN

ANA

MON2

MON1

OOST

UCK1

UCK0

R-0h

Table 7-38. PG1_FAULT Register Field Descriptions

Bit

Field

Type

Reset

Description

7

6

RESERVED

R

0h

PG1_FAULT_TWARN

R

0h

Source for PG1 inactive signal:

0 – TWARN has not set PG1 signal inactive.

1 – TWARN is selected for PG1 signal and it has set PG1 signal

inactive. This bit can be cleared by writing '1' to this bit when TWARN

is valid.

5

4

3

2

1

0

PG1_FAULT_VANA

PG1_FAULT_VMON2

PG1_FAULT_VMON1

PG1_FAULT_BOOST

PG1_FAULT_BUCK1

PG1_FAULT_BUCK0

R

0h

Source for PG1 inactive signal:

0 – VANA has not set PG1 signal inactive.

1 – VANA is selected for PG1 signal and it has set PG1 signal

inactive. This bit can be cleared by writing '1' to this bit when VANA

input is valid.

Source for PG1 inactive signal:

0 – VMON2 has not set PG1 signal inactive.

1 – VMON2 is selected for PG1 signal and it has set PG1 signal

inactive. This bit can be cleared by writing '1' to this bit when VMON2

input is valid.

Source for PG1 inactive signal:

0 – VMON1 has not set PG1 signal inactive.

1 – VMON1 is selected for PG1 signal and it has set PG1 signal

inactive. This bit can be cleared by writing '1' to this bit when VMON1

input is valid.

Source for PG1 inactive signal:

0 – Boost has not set PG1 signal inactive.

1 – Boost is selected for PG1 signal and it has set PG1 signal

inactive. This bit can be cleared by writing '1' to this bit when Boost

output is valid.

Source for PG1 inactive signal:

0 – Buck1 has not set PG1 signal inactive.

1 – Buck1 is selected for PG1 signal and it has set PG1 signal

inactive. This bit can be cleared by writing '1' to this bit when Buck1

output is valid.

Source for PG1 inactive signal:

0 – Buck0 has not set PG1 signal inactive.

1 – Buck0 is selected for PG1 signal and it has set PG1 signal

inactive. This bit can be cleared by writing '1' to this bit when Buck0

output is valid.

7.6.1.1.29 WD_CTRL_1 Register (Offset = 1Ch) [reset = 0h]

WD_CTRL_1 is shown in Figure 7-47 and described in Table 7-39.

Return to Table 7-9.

Figure 7-47. WD_CTRL_1 Register

7

6

5

4

3

2

1

0

WD_CLOSE_TIME

R/W-0h

WD_OPEN_TIME

R/W-0h

WD_LONG_OPEN_TIME

R/W-0h

WD_RESET_CNTR_SEL

R/W-0h

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Table 7-39. WD_CTRL_1 Register Field Descriptions

Bit

Field

Type

Reset

Description

7-6

WD_CLOSE_TIME

R/W

0h

Watchdog close window time select.

00 – 10 ms

01 – 20 ms

10 – 50 ms

11 – 100 ms

(Default from OTP memory)

5-4

3-2

1-0

WD_OPEN_TIME

R/W

0h

Watchdog open window time select.

00 – 20 ms

01 – 100 ms

10 – 200 ms

11 – 600 ms

(Default from OTP memory)

WD_LONG_OPEN_TIME R/W

WD_RESET_CNTR_SEL R/W

Watchdog long open window time select.

00 – 200 ms

01 – 600 ms

10 – 2000 ms

11 – 5000 ms

(Default from OTP memory)

Watchdog reset counter threshold select. After the selected number

of reset (WDR) pulses system restart sequence is initiated.

00 – system restart disabled

01 – 1

10 – 2

11 – 4

(Default from OTP memory)

7.6.1.1.30 WD_CTRL_2 Register (Offset = 1Dh) [reset = 1h]

WD_CTRL_2 is shown in Figure 7-48 and described in Table 7-40.

Return to Table 7-9.

Figure 7-48. WD_CTRL_2 Register

7

6

5

4

3

2

1

0

WD_LOCK

RESERVED

R/W-0h

WD_SYS_RES WD_EN_OTP_

WDI_PD

WDR_POL

WDR_OD

TART_FLAG_M

ODE

READ

R-0h

R/W-0h

R/W-1h

Table 7-40. WD_CTRL_2 Register Field Descriptions

Bit

Field

Type

Reset

Description

7

WD_LOCK

R

0h

Lock bit for watchdog controls. Locks all controls to watchdog in

registers WD_CTRL_1, WD_CTRL_2. Lock bit also locks itself.

Once lock bit is written 1 it cannot be written 0. Only reset can

clear it. 0 – Not locked 1 – Locked WD_STATUS register is not

affected by WD_LOCK bit. WD_SYSTEM_RESTART_FLAG and

WD_RESET_CNTR_STATUS can be cleared even if WD_LOCK=1.

6-5

4

RESERVED

R/W

0h

WD_SYS_RESTART_FLA R/W

G_MODE

WD_SYSTEM_RESTART_FLAG mode select. 0 -

WD_SYSTEM_RESTART_FLAG is only a status bit. 1 –

WD_SYSTEM_RESTART_FLAG prevents further system restarts

until it is cleared. (Default from OTP memory)

3

WD_EN_OTP_READ

R/W

0h

Read OTP during system restart sequence 0 – OTP read not

enabled during system restart sequence 1 – OTP read enabled

during system restart sequence (Default from OTP memory)

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Table 7-40. WD_CTRL_2 Register Field Descriptions (continued)

Bit

Field

Type

Reset

Description

2

WDI_PD

R/W

0h

Selects the pull down resistor on the WDI pin:

0 – Pull-down resistor is disabled

1 – Pull-down resistor is enabled

(Default from OTP memory)

1

0

WDR_POL

WDR_OD

R/W

0h

1h

Watchdog reset output (WDR) polarity select 0 – Active high 1 –

Active low (Default from OTP memory)

Watchdog reset output (WDR) signal type 0 – Push-pull output

(VANA level) 1 – Open-drain output (Default from OTP memory)

7.6.1.1.31 WD_STATUS Register (Offset = 1Eh) [reset = 0h]

WD_STATUS is shown in Figure 7-49 and described in Table 7-41.

Return to Table 7-9.

Figure 7-49. WD_STATUS Register

7

6

5

4

3

2

1

0

RESERVED

WD_CLR_SYS WD_SYSTEM_ WD_CLR_RES

WD_RESET_CNTR_STATUS

TEM_RESTART RESTART_FLA

ET_CNTR

_FLAG

G

R/W-0h

R-0h

Table 7-41. WD_STATUS Register Field Descriptions

Bit

Field

Type

R/W

R

Reset

Description

7-5

4

RESERVED

0h

WD_CLR_SYSTEM_RES

TART_FLAG

0h

Clear bit for WD_SYSTEM_RESTART_FLAG. Write 1 to generate a

clear pulse. Reg bit value returns to 0 after clearing is finished.

3

WD_SYSTEM_RESTART

_FLAG

R

0h

Watchdog requested system restart has occurred. Can be cleared by

writing WD_CLR_SYSTEM_RESTART_FLAG bit 1.

2

WD_CLR_RESET_CNTR

0h

Watchdog reset counter clear. Write 1 to generate a clear pulse.

Current status of watchdog reset counter.

1-0

WD_RESET_CNTR_STAT R

US

7.6.1.1.32 RESET Register (Offset = 1Fh) [reset = 0h]

RESET is shown in Figure 7-50 and described in Table 7-42.

Return to Table 7-9.

Figure 7-50. RESET Register

7

6

5

4

3

2

1

0

RESERVED

R/W-0h

SW_RESET

R-0h

Table 7-42. RESET Register Field Descriptions

Bit

Field

Type

R/W

R

Reset

Description

7-1

0

RESERVED

SW_RESET

0h

Software commanded reset. When written to 1, the registers will be

reset to default values and OTP memory is read.

The bit is automatically cleared.

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7.6.1.1.33 INT_TOP_1 Register (Offset = 20h) [reset = 0h]

INT_TOP_1 is shown in Figure 7-51 and described in Table 7-43.

Return to Table 7-9.

Figure 7-51. INT_TOP_1 Register

7

6

5

4

3

2

1

0

I_MEAS_INT

DIAG_INT

BOOST_INT

BUCK_INT

R-0h

SYNC_CLK_IN TDIE_SD_INT TDIE_WARN_I

OVP_INT

T

NT

R-0h

Table 7-43. INT_TOP_1 Register Field Descriptions

Bit

Field

I_MEAS_INT

Type

Reset

Description

7

R

0h

Latched status bit indicating that the load current measurement

result is available in I_LOAD_1 and I_LOAD_2 registers.

Write 1 to clear interrupt.

6

5

4

DIAG_INT

R

0h

Interrupt indicating that INT_DIAG register has a pending interrupt.

The reason for the interrupt is indicated in INT_DIAG register.

This bit is cleared automatically when INT_DIAG register is cleared

to 0x00.

BOOST_INT

BUCK_INT

Interrupt indicating that BOOST have a pending interrupt. The

reason for the interrupt is indicated in INT_BOOST register.

This bit is cleared automatically when INT_BOOST register is

cleared to 0x00.

Interrupt indicating that BUCK0 or BUCK1 have a pending interrupt.

The reason for the interrupt is indicated in INT_BUCK register.

This bit is cleared automatically when INT_BUCK register is cleared

to 0x00.

3

2

SYNC_CLK_INT

TDIE_SD_INT

R

0h

Latched status bit indicating that the external clock frequency

became valid or invalid.

Write 1 to clear interrupt.

Latched status bit indicating that the die junction temperature has

exceeded the thermal shutdown level. The converters have been

disabled if they were enabled. The converters cannot be enabled if

this bit is active. The actual status of the thermal warning is indicated

by TDIE_SD_STAT bit in TOP_STATUS register.

Write 1 to clear interrupt. Clearing TSD interrupt automatically re-

enables converters. Clearing this interrupt will also clear thermal

warning status.

1

0

TDIE_WARN_INT

OVP_INT

R

0h

Latched status bit indicating that the die junction temperature has

exceeded the thermal warning level. The actual status of the thermal

warning is indicated by TDIE_WARN_STAT bit in TOP_STATUS

register.

Write 1 to clear interrupt.

Latched status bit indicating that the input voltage has exceeded the

over-voltage detection level. The actual status of the over-voltage is

indicated by OVP bit in TOP_STATUS register.

Write 1 to clear interrupt.

7.6.1.1.34 INT_TOP_2 Register (Offset = 21h) [reset = 0h]

INT_TOP_2 is shown in Figure 7-52 and described in Table 7-44.

Return to Table 7-9.

Figure 7-52. INT_TOP_2 Register

7

6

5

4

3

2

1

0

RESERVED

RESET_REG_I

NT

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Figure 7-52. INT_TOP_2 Register (continued)

R/W-0h

R-0h

Table 7-44. INT_TOP_2 Register Field Descriptions

Bit

7-1

0

Field

Type

R/W

R

Reset

Description

RESERVED

RESET_REG_INT

0h

Latched status bit indicating that either VANA supply voltage has

been below undervoltage threshold level or the host has requested a

reset (SW_RESET bit in RESET register). The converters have been

disabled, and registers are reset to default values and the normal

startup procedure is done.

Write 1 to clear interrupt.

7.6.1.1.35 INT_BUCK Register (Offset = 22h) [reset = 0h]

INT_BUCK is shown in Figure 7-53 and described in Table 7-45.

Return to Table 7-9.

Figure 7-53. INT_BUCK Register

7

6

5

4

3

2

1

0

RESERVED

BUCK1_PG_IN BUCK1_SC_IN BUCK1_ILIM_I

RESERVED

R/W-0h

BUCK0_PG_IN BUCK0_SC_IN BUCK0_ILIM_I

T

NT

T

NT

R/W-0h

R-0h

Table 7-45. INT_BUCK Register Field Descriptions

Bit

7

Field

RESERVED

Type

R/W

R

Reset

Description

0h

6

BUCK1_PG_INT

0h

Latched status bit indicating that BUCK1 powergood event has been

detected.

Write 1 to clear.

5

4

BUCK1_SC_INT

R

0h

Latched status bit indicating that the BUCK1 output voltage has

fallen below 0.35 V level during operation or BUCK1 output didn't

reach 0.35 V level in 1 ms from enable.

Write 1 to clear.

BUCK1_ILIM_INT

Latched status bit indicating that BUCK1 output current limit has

been triggered.

Write 1 to clear.

3

2

RESERVED

R/W

R

0h

BUCK0_PG_INT

Latched status bit indicating that BUCK0 powergood event has been

detected.

Write 1 to clear.

1

0

BUCK0_SC_INT

BUCK0_ILIM_INT

R

0h

Latched status bit indicating that the BUCK0 output voltage has

fallen below 0.35 V level during operation or BUCK0 output didn't

reach 0.35 V level in 1 ms from enable.

Write 1 to clear.

Latched status bit indicating that BUCK0 output current limit has

been triggered.

Write 1 to clear.

7.6.1.1.36 INT_BOOST Register (Offset = 23h) [reset = 0h]

INT_BOOST is shown in Figure 7-54 and described in Table 7-46.

Return to Table 7-9.

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Figure 7-54. INT_BOOST Register

7

6

5

4

3

2

1

0

RESERVED

BOOST_PG_IN BOOST_SC_IN BOOST_ILIM_I

T

NT

R/W-0h

R-0h

Table 7-46. INT_BOOST Register Field Descriptions

Bit

7-3

2

Field

Type

R/W

R

Reset

Description

RESERVED

0h

BOOST_PG_INT

0h

Latched status bit indicating that Boost powergood event has been

detected.

Write 1 to clear.

1

0

BOOST_SC_INT

BOOST_ILIM_INT

R

0h

Latched status bit indicating that the Boost output voltage has fallen

to input voltage level or below 2.5 V level during operation or BOOST

output didn't reach 2.5 V level in 1 ms from enable.

Write 1 to clear.

Latched status bit indicating that Boost output current limit has been

triggered.

Write 1 to clear.

7.6.1.1.37 INT_DIAG Register (Offset = 24h) [reset = 0h]

INT_DIAG is shown in Figure 7-55 and described in Table 7-47.

Return to Table 7-9.

Figure 7-55. INT_DIAG Register

7

6

5

4

3

2

1

0

RESERVED

VMON2_PG_IN RESERVED VMON1_PG_IN RESERVED

VANA_PG_INT

T

R/W-0h

R-0h

R/W-0h

R-0h

R/W-0h

R-0h

Table 7-47. INT_DIAG Register Field Descriptions

Bit

Field

Type

R/W

R

Reset

Description

7-5

4

RESERVED

0h

VMON2_PG_INT

0h

Latched status bit indicating that VMON2 powergood event has been

detected.

Write 1 to clear.

3

2

RESERVED

R/W

R

0h

VMON1_PG_INT

Latched status bit indicating that VMON1 powergood event has been

detected.

Write 1 to clear.

1

0

RESERVED

R/W

R

0h

VANA_PG_INT

Latched status bit indicating that VANA powergood event has been

detected.

Write 1 to clear.

7.6.1.1.38 TOP_STATUS Register (Offset = 25h) [reset = 0h]

TOP_STATUS is shown in Figure 7-56 and described in Table 7-48.

Return to Table 7-9.

Figure 7-56. TOP_STATUS Register

7

6

5

4

3

2

1

0

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Figure 7-56. TOP_STATUS Register (continued)

RESERVED

SYNC_CLK_ST TDIE_SD_STAT TDIE_WARN_S

OVP_STAT

R-0h

AT

TAT

R-0h

Table 7-48. TOP_STATUS Register Field Descriptions

Bit

7-4

3

Field

Type

Reset

Description

RESERVED

SYNC_CLK_STAT

R

0h

R

0h

Status bit indicating the status of external clock (CLKIN):

0 – External clock frequency is valid

1 – External clock frequency is not valid.

2

1

0

TDIE_SD_STAT

TDIE_WARN_STAT

OVP_STAT

R

0h

Status bit indicating the status of thermal shutdown:

0 – Die temperature below thermal shutdown level

1 – Die temperature above thermal shutdown level.

Status bit indicating the status of thermal warning:

0 – Die temperature below thermal warning level

1 – Die temperature above thermal warning level.

Status bit indicating the status of input overvoltage monitoring:

0 – Input voltage below overvoltage threshold level

1 – Input voltage above overvoltage threshold level.

7.6.1.1.39 BUCK_STATUS Register (Offset = 26h) [reset = 0h]

BUCK_STATUS is shown in Figure 7-57 and described in Table 7-49.

Return to Table 7-9.

Figure 7-57. BUCK_STATUS Register

7

6

5

4

3

2

1

0

BUCK1_STAT BUCK1_PG_ST

AT

BUCK1_ILIM_S BUCK0_STAT BUCK0_PG_ST

BUCK0_ILIM_S

TAT

AT

R-0h

Table 7-49. BUCK_STATUS Register Field Descriptions

Bit

Field

Type

Reset

Description

7

6

4

3

2

0

BUCK1_STAT

R

0h

Status bit indicating the enable or disable status of BUCK1:

0 – BUCK1 converter is disabled

1 – BUCK1 converter is enabled.

BUCK1_PG_STAT

BUCK1_ILIM_STAT

BUCK0_STAT

R

0h

Status bit indicating BUCK1 output voltage validity (raw status)

0 – BUCK1 output is not valid

1 – BUCK1 output is valid.

Status bit indicating BUCK1 current limit status (raw status)

0 – BUCK1 output current is below current limit threshold level

1 – BUCK1 output current is at current limit threshold level.

Status bit indicating the enable or disable status of BUCK0:

0 – BUCK0 converter is disabled

1 – BUCK0 converter is enabled.

BUCK0_PG_STAT

BUCK0_ILIM_STAT

Status bit indicating BUCK0 output voltage validity (raw status)

0 – BUCK0 output is not valid

1 – BUCK0 output is valid.

Status bit indicating BUCK0 current limit status (raw status)

0 – BUCK0 output current is below current limit threshold level

1 – BUCK0 output current is at current limit threshold level.

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7.6.1.1.40 BOOST_STATUS Register (Offset = 27h) [reset = 0h]

BOOST_STATUS is shown in Figure 7-58 and described in Table 7-50.

Return to Table 7-9.

Figure 7-58. BOOST_STATUS Register

7

6

5

4

3

2

1

0

RESERVED

R-0h

BOOST_STAT BOOST_PG_S

TAT

BOOST_ILIM_S

TAT

R-0h

Table 7-50. BOOST_STATUS Register Field Descriptions

Bit

Field

Type

Reset

Description

7-4

3

RESERVED

R

0h

BOOST_STAT

R

0h

Status bit indicating the enable/disable status of Boost:

0 – Boost converter is disabled

1 – Boost converter is enabled.

2

0

BOOST_PG_STAT

BOOST_ILIM_STAT

R

0h

Status bit indicating Boost output voltage validity (raw status)

0 – Boost output is not valid

1 – Boost output is valid.

Status bit indicating Boost current limit status (raw status)

0 – Boost output current is below current limit threshold level

1 – Boost output current is at current limit threshold level.

7.6.1.1.41 DIAG_STATUS Register (Offset = 28h) [reset = 0h]

DIAG_STATUS is shown in Figure 7-59 and described in Table 7-51.

Return to Table 7-9.

Figure 7-59. DIAG_STATUS Register

7

6

5

4

3

2

1

0

RESERVED

VMON2_PG_S

TAT

RESERVED

VMON1_PG_S

TAT

RESERVED

VANA_PG_STA

T

R-0h

Table 7-51. DIAG_STATUS Register Field Descriptions

Bit

Field

Type

Reset

Description

7-5

4

RESERVED

R

0h

VMON2_PG_STAT

R

0h

Status bit indicating VMON2 input voltage validity (raw status)

0 – VMON2 voltage is not valid

1 – VMON2 voltage is valid.

3

2

RESERVED

R

0h

VMON1_PG_STAT

Status bit indicating VMON1 input voltage validity (raw status)

0 – VMON1 voltage is not valid

1 – VMON1 voltage is valid.

1

0

RESERVED

R

0h

VANA_PG_STAT

Status bit indicating VANA input voltage validity (raw status)

0 – VANA voltage is not valid

1 – VANA voltage is valid.

7.6.1.1.42 TOP_MASK_1 Register (Offset = 29h) [reset = 0h]

TOP_MASK_1 is shown in Figure 7-60 and described in Table 7-52.

Return to Table 7-9.

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Figure 7-60. TOP_MASK_1 Register

7

6

5

4

3

2

1

0

I_MEAS_MASK

RESERVED

SYNC_CLK_M

ASK

RESERVED TDIE_WARN_M RESERVED

ASK

R/W-0h

Table 7-52. TOP_MASK_1 Register Field Descriptions

Bit

Field

Type

Reset

Description

7

I_MEAS_MASK

R/W

0h

Masking for load current measurement ready interrupt I_MEAS_INT

in INT_TOP_1 register.

0 – Interrupt generated

1 – Interrupt not generated.

(Default from OTP memory)

6-4

3

RESERVED

R/W

0h

SYNC_CLK_MASK

Masking for external clock detection interrupt SYNC_CLK_INT in

INT_TOP_1 register:

0 – Interrupt generated

1 – Interrupt not generated.

(Default from OTP memory)

2

1

RESERVED

R/W

0h

TDIE_WARN_MASK

Masking for thermal warning interrupt TDIE_WARN_INT in

INT_TOP_1 register:

0 – Interrupt generated

1 – Interrupt not generated.

This bit does not affect TDIE_WARN_STAT status bit in

TOP_STATUS register.

(Default from OTP memory)

0

RESERVED

R/W

0h

7.6.1.1.43 TOP_MASK_2 Register (Offset = 2Ah) [reset = 1h]

TOP_MASK_2 is shown in Figure 7-61 and described in Table 7-53.

Return to Table 7-9.

Figure 7-61. TOP_MASK_2 Register

7

6

5

4

3

2

1

0

RESERVED

RESET_REG_

MASK

R/W-0h

R/W-1h

Table 7-53. TOP_MASK_2 Register Field Descriptions

Bit

Field

Type

R/W

Reset

Description

7-1

0

RESERVED

0h

RESET_REG_MASK

1h

Masking for register reset interrupt RESET_REG_INT in INT_TOP_2

register:

0 – Interrupt generated

1 – Interrupt not generated.

(Default from OTP memory)

7.6.1.1.44 BUCK_MASK Register (Offset = 2Bh) [reset = 0h]

BUCK_MASK is shown in Figure 7-62 and described in Table 7-54.

Return to Table 7-9.

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Figure 7-62. BUCK_MASK Register

7

6

5

4

3

2

1

0

BUCK1_PGF_ BUCK1_PGR_

RESERVED BUCK1_ILIM_M BUCK0_PGF_ BUCK0_PGR_

RESERVED BUCK0_ILIM_M

ASK

MASK

ASK

MASK

R/W-0h

Table 7-54. BUCK_MASK Register Field Descriptions

Bit

Field

Type

Reset

Description

7

BUCK1_PGF_MASK

R/W

0h

Masking of powergood invalid detection for BUCK1 power good

interrupt BUCK1_PG_INT in INT_BUCK register:

0 – Interrupt generated

1 – Interrupt not generated.

This bit does not affect BUCK1_PG_STAT status bit in

BUCK_STATUS register.

(Default from OTP memory)

6

BUCK1_PGR_MASK

R/W

0h

Masking of powergood valid detection for BUCK1 power good

interrupt BUCK1_PG_INT in INT_BUCK register:

0 – Interrupt generated

1 – Interrupt not generated.

This bit does not affect BUCK1_PG_STAT status bit in

BUCK_STATUS register.

(Default from OTP memory)

5

4

RESERVED

R/W

0h

BUCK1_ILIM_MASK

Masking for BUCK1 current monitoring interrupt BUCK1_ILIM_INT in

INT_BUCK register:

0 – Interrupt generated

1 – Interrupt not generated.

This bit does not affect BUCK1_ILIM_STAT status bit in

BUCK_STATUS register.

(Default from OTP memory)

3

2

BUCK0_PGF_MASK

BUCK0_PGR_MASK

R/W

0h

Masking of powergood invalid detection for BUCK0 power good

interrupt BUCK0_PG_INT in INT_BUCK register:

0 – Interrupt generated

1 – Interrupt not generated.

This bit does not affect BUCK0_PG_STAT status bit in

BUCK_STATUS register.

(Default from OTP memory)

Masking of powergood valid detection for BUCK0 power good

interrupt BUCK0_PG_INT in INT_BUCK register:

0 – Interrupt generated

1 – Interrupt not generated.

This bit does not affect BUCK0_PG_STAT status bit in

BUCK_STATUS register.

(Default from OTP memory)

1

0

RESERVED

R/W

0h

BUCK0_ILIM_MASK

Masking for BUCK0 current monitoring interrupt BUCK0_ILIM_INT in

INT_BUCK register:

0 – Interrupt generated

1 – Interrupt not generated.

This bit does not affect BUCK0_ILIM_STAT status bit in

BUCK_STATUS register.

(Default from OTP memory)

7.6.1.1.45 BOOST_MASK Register (Offset = 2Ch) [reset = 0h]

BOOST_MASK is shown in Figure 7-63 and described in Table 7-55.

Return to Table 7-9.

Figure 7-63. BOOST_MASK Register

7

6

5

4

3

2

1

0

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Figure 7-63. BOOST_MASK Register (continued)

RESERVED

BOOST_PGF_ BOOST_PGR_

RESERVED

R/W-0h

BOOST_ILIM_

MASK

R/W-0h

Table 7-55. BOOST_MASK Register Field Descriptions

Bit

7-4

3

Field

Type

R/W

Reset

Description

RESERVED

BOOST_PGF_MASK

0h

Masking of powergood invalid detection for Boost power good

interrupt BOOST_PG_INT in INT_BOOST register:

0 – Interrupt generated

1 – Interrupt not generated.

This bit does not affect BOOST_PG_STAT status bit in

BOOST_STATUS register.

(Default from OTP memory)

2

BOOST_PGR_MASK

R/W

0h

Masking of powergood valid detection for Boost power good interrupt

BOOST_PG_INT in INT_BOOST register:

0 – Interrupt generated

1 – Interrupt not generated.

This bit does not affect BOOST_PG_STAT status bit in

BOOST_STATUS register.

(Default from OTP memory)

1

0

RESERVED

R/W

0h

BOOST_ILIM_MASK

Masking for Boost current monitoring interrupt BOOST_ILIM_INT in

INT_BOOST register:

0 – Interrupt generated

1 – Interrupt not generated.

This bit does not affect BOOST_ILIM_STAT status bit in

BOOST_STATUS register.

(Default from OTP memory)

7.6.1.1.46 DIAG_MASK Register (Offset = 2Dh) [reset = 0h]

DIAG_MASK is shown in Figure 7-64 and described in Table 7-56.

Return to Table 7-9.

Figure 7-64. DIAG_MASK Register

7

6

5

4

3

2

1

0

RESERVED

R/W-0h

VMON2_PGF_ VMON2_PGR_ VMON1_PGF_ VMON1_PGR_ VANA_PGF_M VANA_PGR_M

MASK

ASK

R/W-0h

Table 7-56. DIAG_MASK Register Field Descriptions

Bit

Field

Type

R/W

Reset

Description

7-6

5

RESERVED

0h

VMON2_PGF_MASK

0h

Masking of VMON2 invalid detection for powergood interrupt

VMON2_PG_INT in INT_DIAG register:

0 – Interrupt generated

1 – Interrupt not generated.

This bit does not affect VMON2_PG_STAT status bit in

DIAG_STATUS register.

(Default from OTP memory)

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Table 7-56. DIAG_MASK Register Field Descriptions (continued)

Bit

Field

Type

Reset

Description

4

VMON2_PGR_MASK

R/W

0h

Masking of VMON2 valid detection for powergood interrupt

VMON2_PG_INT in INT_DIAG register:

0 – Interrupt generated

1 – Interrupt not generated.

This bit does not affect VMON2_PG_STAT status bit in

DIAG_STATUS register.

(Default from OTP memory)

3

2

1

0

VMON1_PGF_MASK

VMON1_PGR_MASK

VANA_PGF_MASK

VANA_PGR_MASK

R/W

0h

Masking of VMON1 invalid detection for powergood interrupt

VMON1_PG_INT in INT_DIAG register:

0 – Interrupt generated

1 – Interrupt not generated.

This bit does not affect VMON1_PG_STAT status bit in

DIAG_STATUS register.

(Default from OTP memory)

Masking of VMON1 valid detection for powergood interrupt

VMON1_PG_INT in INT_DIAG register:

0 – Interrupt generated

1 – Interrupt not generated.

This bit does not affect VMON1_PG_STAT status bit in

DIAG_STATUS register.

(Default from OTP memory)

Masking of VANA invalid detection for powergood interrupt

VANA_PG_INT in INT_DIAG register:

0 – Interrupt generated

1 – Interrupt not generated.

This bit does not affect VANA_PG_STAT status bit in DIAG_STATUS

register.

(Default from OTP memory)

Masking of VANA valid detection for powergood interrupt

VANA_PG_INT in INT_DIAG register:

0 – Interrupt generated

1 – Interrupt not generated.

This bit does not affect VANA_PG_STAT status bit in DIAG_STATUS

register.

(Default from OTP memory)

7.6.1.1.47 SEL_I_LOAD Register (Offset = 2Eh) [reset = 0h]

SEL_I_LOAD is shown in Figure 7-65 and described in Table 7-57.

Return to Table 7-9.

Figure 7-65. SEL_I_LOAD Register

7

6

5

4

3

2

1

0

RESERVED

R/W-0h

LOAD_CURRENT_BUCK_SELE

CT

R/W-0h

Table 7-57. SEL_I_LOAD Register Field Descriptions

Bit

Field

RESERVED

Type

Reset

Description

7-2

1-0

R/W

0h

LOAD_CURRENT_BUCK R/W

_SELECT

0h

Start the current measurement on the selected Buck converter:

0 – BUCK0

1 – BUCK1

2 – BUCK0

3 – BUCK1

The measurement is started when register is written.

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7.6.1.1.48 I_LOAD_2 Register (Offset = 2Fh) [reset = 0h]

I_LOAD_2 is shown in Figure 7-66 and described in Table 7-58.

Return to Table 7-9.

Figure 7-66. I_LOAD_2 Register

7

6

5

4

3

2

1

0

RESERVED

BUCK_LOAD_

CURRENT_8

R-0h

Table 7-58. I_LOAD_2 Register Field Descriptions

Bit

Field

Type

Reset

Description

7-1

0

RESERVED

R

0h

BUCK_LOAD_CURRENT

_8

R

0h

This register describes the MSB bit of the average load current on

selected converter with a resolution of 20 mA per LSB and maximum

10 A current.

7.6.1.1.49 I_LOAD_1 Register (Offset = 30h) [reset = 0h]

I_LOAD_1 is shown in Figure 7-67 and described in Table 7-59.

Return to Table 7-9.

Figure 7-67. I_LOAD_1 Register

7

6

5

4

3

2

1

0

BUCK_LOAD_CURRENT_7_0

R-0h

Table 7-59. I_LOAD_1 Register Field Descriptions

Bit

7-0

Field

Type

Reset

Description

BUCK_LOAD_CURRENT

_7_0

R

0h

This register describes 8 LSB bits of the average load current on

selected converter with a resolution of 20 mA per LSB and maximum

10 A current.

7.6.1.1.50 FREQ_SEL Register (Offset = 31h) [reset = 0h]

FREQ_SEL is shown in Figure 7-68 and described in Table 7-60.

Return to Table 7-9.

Figure 7-68. FREQ_SEL Register

7

6

5

4

3

2

1

0

RESERVED

R/W-0h

BOOST_FREQ

_SEL

BUCK_FREQ_SEL

R-0h

Table 7-60. FREQ_SEL Register Field Descriptions

Bit

Field

Type

R/W

R

Reset

Description

7-3

2

RESERVED

0h

BOOST_FREQ_SEL

0h

Boost switching frequency:

0 – 2 MHz

1 – 4 MHz

(Default from OTP memory)

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Table 7-60. FREQ_SEL Register Field Descriptions (continued)

Bit

Field

Type

Reset

Description

1-0

BUCK_FREQ_SEL

R

0h

Buck0 and Buck1 switching frequency:

0x0 – 2 MHz

0x1 – 3 MHz

0x2 – 4 MHz

0x3 – 4 MHz

(Default from OTP memory)

7.6.1.1.51 BOOST_ILIM_CTRL Register (Offset = 32h) [reset = 0h]

BOOST_ILIM_CTRL is shown in Figure 7-69 and described in Table 7-61.

Return to Table 7-9.

Figure 7-69. BOOST_ILIM_CTRL Register

7

6

5

4

3

2

1

0

RESERVED

R/W-0h

BOOST_ILIM

R/W-0h

Table 7-61. BOOST_ILIM_CTRL Register Field Descriptions

Bit

Field

Type

R/W

Reset

Description

7-2

1-0

RESERVED

BOOST_ILIM

0h

Sets the current limit of Boost.

00 – 1.0 A

01 – 1.4 A

10 – 1.9 A

11 – 2.8 A

(Default from OTP memory)

7.6.1.1.52 ECC_STATUS Register (Offset = 33h) [reset = 0h]

ECC_STATUS is shown in Figure 7-70 and described in Table 7-62.

Return to Table 7-9.

Figure 7-70. ECC_STATUS Register

7

6

5

4

3

2

1

0

RESERVED

R-0h

DED

R-0h

SED

R-0h

Table 7-62. ECC_STATUS Register Field Descriptions

Bit

Field

Type

Reset

Description

7-2

1

RESERVED

DED

R

0h

R

0h

OTP error correction status: 0 – No dual errors detected 1 – Dual

errors detected and not corrected

0

SED

R

0h

OTP error correction status: 0 – No single errors detected 1 – Single

errors detected and corrected

7.6.1.1.53 WD_DIS_CTRL_CODE Register (Offset = 34h) [reset = 0h]

WD_DIS_CTRL_CODE is shown in Figure 7-71 and described in Table 7-63.

Return to Table 7-9.

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Figure 7-71. WD_DIS_CTRL_CODE Register

7

6

5

4

3

2

1

0

WD_DIS_UNLOCK_CODE

R-0h

Table 7-63. WD_DIS_CTRL_CODE Register Field Descriptions

Bit

Field

Type

Reset

Description

7-0

WD_DIS_UNLOCK_COD

E

R

0h

Unlocking WD_DIS_CTRL bit: Set WD_DIS_CTRL_LOCK=0 by

writing 0x87, 0x65, 0x1B by 3 consecutive I2C write sequences to

WD_DIS_CTRL_CODE register.

Locking WD_DIS_CTRL bit: Set WD_DIS_CTRL_LOCK=1 by writing

anything to WD_DIS_CTRL_CODE register or write WD_LOCK=1.

Reading this address returns always 0x00. WD_DIS_CTRL can be

unlocked only if WD_LOCK=0.

7.6.1.1.54 WD_DIS_CONTROL Register (Offset = 35h) [reset = 0h]

WD_DIS_CONTROL is shown in Figure 7-72 and described in Table 7-64.

Return to Table 7-9.

Figure 7-72. WD_DIS_CONTROL Register

7

6

5

4

3

2

1

0

RESERVED

R/W-0h

WD_DIS_CTRL WD_DIS_CTRL

_LOCK

R-1h

R/W-0h

Table 7-64. WD_DIS_CONTROL Register Field Descriptions

Bit

Field

Type

R/W

R

Reset

Description

7-2

1

RESERVED

0h

WD_DIS_CTRL_LOCK

1h

Lock status for WD_DIS_CTRL bit.

0 – Not locked, WD_DIS_CTRL bit can be written.

1 – Locked, WD_DIS_CTRL bit is locked and cannot be changed.

Lock can be opened by writing 0x87, 0x65, 0x1B by 3

consecutive I2C write sequences to WD_DIS_CTRL_CODE register

if WD_LOCK=0. Lock can be closed by writing anything to

WD_DIS_CTRL_CODE register or writing WD_LOCK=1.

0

WD_DIS_CTRL

R/W

0h

Watchdog disable pin control.

0 – Watchdog cannot be disabled by WD_DIS pin.

1 – Watchdog can be disabled by WD_DIS pin.

(Default from OTP memory)

This bit can be written 1 only if WD_LOCK=0 and

WD_DIS_CTRL_LOCK=0.

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8 Application and Implementation

Note

Information in the following applications sections is not part of the TI component specification,

and TI does not warrant its accuracy or completeness. TI’s customers are responsible for

determining suitability of components for their purposes, as well as validating and testing their design

implementation to confirm system functionality.

8.1 Application Information

The LP87702 is a power-management unit including a boost converter, two step-down converters, and three

general-purpose digital output signals.

8.2 Typical Application

V_IN

VIN_B0

VIN_B1

L₀

VOUT0

C_IN0

C_IN1

SW_B0

FB_B0

LOAD

C_OUT0

VANA

C_ANA

L₁

VOUT1

L₂

SW_B1

FB_B1

LOAD

SW_BST

C_OUT1

NRST

SDA (EN3)

SCL (EN2)

nINT

VOUT2

EN1

VOUT_BST

LOAD

CLKIN (GPO2)

PG0

PG1 (GPO1)

GPO0

C_OUT2

VMON1

VMON2

WDI

WD_RESET

GNDs

Figure 8-1. LP87702 Typical Application

8.2.1 Design Requirements

Table 8-1. Design Parameters

DESIGN PARAMETER

Input voltage

EXAMPLE VALUE

3.3 V

Output voltages

1.8 V, 1.24 V, 5 V

4 MHz

Switching frequency

8.2.2 Detailed Design Procedure

The performance of the LP87702 device depends greatly on the care taken in designing the printed circuit board

(PCB). The use of low-inductance and low serial-resistance ceramic capacitors is strongly recommended, while

proper grounding is crucial. Attention should be given to decoupling the power supplies. Decoupling capacitors

must be connected close to the device and between the power and ground pins to support high peak currents

being drawn from the system power rail while turning on the switching MOSFETs. Keep input and output traces

as short as possible, because trace inductance, resistance, and capacitance can easily become the performance

limiting items. The separate buck converter power pins VIN_Bx are not connected together internally. The

VIN_Bx power connections shall be connected together outside the package using a power plane construction.

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8.2.2.1 Application Components

8.2.2.1.1 Inductor Selection

Section 8.2 shows the inductors L₀, L₁, and L₂. The inductor's inductance and DCR affects the buck and boost

converter's control loop. Table 8-2 lists the recommended inductors, or similar ones, that should be used. Pay

attention to the inductor's saturation current and temperature rise current. Check that the saturation current

is higher than the peak current limit and the temperature rise current is higher than the maximum expected

rms output current. Section 6 shows the minimum effective inductance that ensures good performance. The

inductor's DC resistance should be less than 0.05 Ω for good efficiency at high-current condition. The inductor

AC loss (resistance) also affects conversion efficiency. Higher Q factor at switching frequency usually gives

better efficiency at light load to middle load. Shielded inductors are preferred as they radiate less noise.

Table 8-2. Recommended Inductors for Buck Converters

MANUFACTURER

PART NUMBER

VALUE

DIMENSIONS

L × W x× H (mm)

RATED DC CURRENT,

I_SATmax / I_TEMPmax (A)

DCR typ / max

(mΩ)

MURATA

DFE20162E-R47M

DFE252012F-R47M

0.47 µH (20%)

2 × 1.6 × 1.2

2.5 × 2 × 1.2

5.5 / 4.5⁽¹⁾

6.7 / 4.9⁽¹⁾

- / 26

- / 23

(1) Operating temperature range is up to 125°C including self temperature rise.

Table 8-3. Recommended Inductor for Boost Converters

MANUFACTURER

PART NUMBER

VALUE

DIMENSIONS

L × W x× H (mm)

RATED DC CURRENT,

I_SATmax / I_TEMPmax (A)

DCR typ / max

(mΩ)

MURATA

DFE201612E-1R0M

DFE252012F-1R0M

1 µH (20%)

2 × 1.6 × 1.2

2.5 × 2 × 1.2

4.0 / 2.9 ⁽¹⁾

4.2 / 3.3 ⁽¹⁾

- / 42

- / 40

8.2.2.1.2 Buck Input Capacitor Selection

Section 8.2 shows the input capacitors C_IN0and C_IN1. A ceramic input bypass capacitor of 10 μF is required

for both converters. Place the input capacitor as close as possible to the device's VIN_Bx pin and PGND_Bx

pin. A larger value or higher voltage rating improves the input voltage filtering. Use X7R type of capacitors, not

Y5V or F. The capacitor's DC bias characteristics must also be considered. Minimum effective input capacitance

to ensure good performance is 1.9 μF per buck input at the maximum input voltage including tolerances and

ambient temperature range. In addition, Table 8-4 shows how there must be at least 22 μF of additional

capacitance common for all the power input pins on the system power rail.

The input filter capacitor supplies current to the high-side FET switch in the first half of each cycle and reduces

the voltage ripple imposed on the input power source. A ceramic capacitor's low ESR provides the best noise

filtering of the input voltage spikes due to this rapidly changing current. Select an input filter capacitor with

sufficient ripple current rating. In addition, ferrite can be used in front of the input capacitor to reduce the EMI.

Table 8-4. Recommended Buck Input Capacitors (X7R Dielectric)

MANUFACTURER

PART NUMBER

VALUE

CASE SIZE

DIMENSIONS LxWxH VOLTAGE RATING

(mm)

Murata

TDK

GRM21BR71A06KA73

10 µF (10%)

0805

2 × 1.25 × 1.25

10 V

C2012X7R1A106K125AC

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8.2.2.1.3 Buck Output Capacitor Selection

Section 8.2 shows the output capacitor C_OUT0and C_OUT1. A ceramic local output capacitor of 22 μF is

required for both outputs. Use ceramic capacitors, X7R or X7T types; do not use Y5V or F. DC bias voltage

characteristics of ceramic capacitors must be considered. The output filter capacitor smooths out the current flow

from the inductor to the load, whic helps maintain a steady output voltage during transient load changes and

reduces output voltage ripple. These capacitors must be selected with sufficient capacitance and sufficiently low

ESR and ESL to perform these functions. Minimum effective output capacitance for good performance is 15 μF

for each buck, including the DC voltage roll-off, tolerances, aging, and temperature effects.

The output voltage ripple is caused by charging and discharging the output capacitor, and is also due to its R_ESR

.

Table 8-5 shows how the R_ESRis frequency dependent (as well as temperature dependent); make sure the value

used for selection process is at the part's switching frequency.

POL capacitors can be used to improve load transient performance and to decrease the ripple voltage. A higher

output capacitance improves the load step behavior, reduces the output voltage ripple, and decreases the PFM

switching frequency. Note: the output capacitor may be the limiting factor in the output voltage ramp, especially

for very large (100-μF range) output capacitors. The output voltage might be slower than the programmed

ramp rate at voltage transitions for large output capacitors, because of the higher energy stored on the output

capacitance. Also, the time required to charge the output capacitor to target value might be longer at start-up.

The output voltage is discharged to 0.6 V level using forced-PWM operation at shutdown. This can increase the

input voltage if the load current is small and the output capacitor is large compared to the input capacitor. The

output capacitor is discharged by the internal discharge resistor when below the 0.6 V level, and more time is

required to settle VOUT down with a large capacitor because of the increased time constant.

Table 8-5. Recommended Buck Output Capacitors (X7R or X7T Dielectric)

MANUFACTURER

PART NUMBER

VALUE

CASE SIZE

DIMENSIONS LxWxH VOLTAGE RATING

(mm)

Murata

TDK

GRM21BD71A226ME44

C2012X7S1A226M125AC

22 µF (10%)

22 µF (20%)

0805

2 × 1.25 × 1.25

10 V

8.2.2.1.4 Boost Input Capacitor Selection

A ceramic input capacitor of 10 μF is sufficient for most applications. Place the input capacitor close to the

SW_BST pin of the device. Use X7R types, do not use Y5V or F. See Table 8-6.

Table 8-6. Recommended Boost Input Capacitors (X7R Dielectric)

MANUFACTURER

PART NUMBER

VALUE

CASE SIZE

DIMENSIONS L×W×H VOLTAGE RATING

(mm)

Murata

GRM21BR71A06KA73

10 µF (10%)

0805

2.0 × 1.25 × 1.25

10 V

8.2.2.1.5 Boost Output Capacitor Selection

Use ceramic capacitors, X7R or X7T types; do not use Y5V or F. Place the output capacitor as close as possible

to the device's VOUT_BST pin and PGND_BST pin. DC bias voltage characteristics of ceramic capacitors must

be considered. DC bias characteristics vary from manufacturer to manufacturer, and DC bias curves should

be requested from them as part of the capacitor selection process. These capacitors must be selected with

sufficient capacitance and sufficiently low ESR and ESL to support load transients. See Table 8-7.

Table 8-7. Recommended Boost Output Capacitors (X7R or X7T Dielectric)

MANUFACTURER

PART NUMBER

VALUE

CASE SIZE

DIMENSIONS L×W×H (mm)

VOLTAGE RATING

Murata

GRM21BD71A226ME44

22 µF (10%)

0805

2 × 1.25 × 1.25

10 V

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8.2.2.1.6 Supply Filtering Components

The VANA input is used to supply analog and digital circuits in the device. See Table 8-8 recommended

components from for VANA input supply filtering.

Table 8-8. Recommended Supply Filtering Components

MANUFACTURER

PART NUMBER

VALUE

CASE SIZE

DIMENSIONS L×W×H

(mm)

VOLTAGE RATING

Murata

GRT033C71C104KE01

GCM155R71C104KA55D

0.1 nF (10%)

0201

0402

0.6 × 0.3 × 0.3

1.0 × 0.5 × 0.5

16 V

8.2.3 Current Limit vs Maximum Output Current

The current limit must be set high enough to account for the inductor ripple current on top of the maximum

output current for the buck converters and boost. The forward current limit for the buck converters is set by

BUCK0_ILIM, BUCK1_ILIM and for boost it is set by BOOST_ILIM.

For the buck converter the inductor current ripple can be calculated using Equation 1 and Equation 2:

V_OUT

D =

V

ì h

IN(max)

(1)

(2)

(V_IN(max)- V_OUT) ì D

f_SWì L

DI_L=

Example using Equation 1 and Equation 2:

V_IN(max)= 5.5 V

V_OUT= 1 V

η = 0.75

f_SW= 1.8 MHz

L = 0.38 µH

then D = 0.242 and ΔI_L= 1.59 A

Peak current is half of the current ripple. If I_{LIM_FWD_SET_OTP}is 3 A, the minimum forward current limit would be

2.85 A when taking the –5% tolerance into account. In this case the difference between set peak current and

maximum load current = 0.795 A + 0.15 A = 0.945 A.

Inductor current =

Forward current

I_{LIM_FWD_MAX}(+20%)

I_{LIM_FWD_TYP}(+7.5%)

I_{LIM_FWD_SET_OTP}(1.5...4.5 A, 0.5-A step)

I_{LIM_FWD_MIN}(-5%)

Minimum 1A guard band

to take current ripple,

inductor inductance

variation into account

I_{L_AVG}= I_OUT

1 / f_SW

I_{OUT_MAX}< I_{LIM_FWD_SET_OTP}œ 1 A

Figure 8-2. Current Limit vs Maximum Output Current

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8.2.4 Application Curves

Unless otherwise specified: V_IN= 3.3 V, V_{OUT_BUCK}= 1 V, V_{OUT_BOOST}= 5 V, T_A= 25°C, ƒ_SW-setting 4 MHz, L0 = L1 =

0.47 µH (TOKO DFE252012PD-R47M), L2 = 1 µH (TFM252012ALMA1R0), C_{OUT_BUCK}, C_{POL_BUCK}, and C_{OUT_BOOST}= 22

µF. Measurements are done using connections in Figure 8-1.

100

90

80

70

60

50

100

90

80

70

60

50

40

Vin=3.3V, Vout=1.2V

Vin=3.3V, Vout=1.8V

Vin=5.0V, Vout=1.2V

Vin=5.0V, Vout=1.8V

Vout=1.0V, Vin=3.3V

Vout=1.2V, Vin=3.3V

Vout=1.8V, Vin=3.3V

0.001

0.01

0.1

Output Current (A)

1

5

0.01

0.1

Output Current (A)

1

5

D001

D002

.

V_IN= 3.3 V

Figure 8-3. Buck Efficiency in AUTO (PFM/PWM)

Mode

Figure 8-4. Buck Efficiency in Forced PWM Mode

100

90

80

70

60

1.02

1.015

1.01

1.005

1

0.995

0.99

Vout=1.0V, Vin=5.0V

Vout=1.2V, Vin=5.0V

Vout=1.8V, Vin=5.0V

50

0.985

0.98

Vin=3.3V, FPWM

Vin=5.0V, FPWM

40

0.01

0.1

Output Current (A)

1

5

0

0.5

1

1.5 2

Output Current (A)

2.5

3

3.5

D003

D004

V_IN= 5 V

V_OUT= 1 V

Figure 8-5. Buck Efficiency in Forced PWM Mode Figure 8-6. Buck Output Voltage vs Load Current in

Forced PWM Mode

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1.02

1.015

1.01

1.005

1

1.015

1.01

1.005

1

0.995

0.99

0.985

0.98

0.995

0.99

0.985

0.98

Vin=3.3V, AUTO

Vin=5.0V, AUTO

Vout=1.0V; ILOAD=2.0A

0

0.5

1

1.5 2

Output Current (A)

2.5

3

3.5

2.7

3

3.3 3.6 3.9 4.2 4.5 4.8 5.1 5.4 5.7

Input Voltage (V)

D005

D009

V_OUT= 1 V

.

Figure 8-7. Buck Output Voltage vs Load Current in Figure 8-8. Buck Output Voltage vs Input Voltage in

AUTO Mode PWM Mode

1.02

1.015

1.01

1.005

1

0.995

0.99

0.985

0.98

Vin=3.3V; Vout=1.0V

80 100 120 140

-40

-20

0

20

40 60

Temperature (C)

D010

.

I_OUT= 0 A

Figure 8-9. Buck Output Voltage vs Temperature

Figure 8-10. Buck Start-up with EN1, Forced-PWM

R_LOAD= 1 Ω

Figure 8-12. Buck Shutdown with EN1, Forced-

PWM

Figure 8-11. Buck Start-up with EN1, Forced-PWM

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V_OUT= 1.2 V

I_OUT= 500 mA

V_OUT= 1.2 V

I_OUT= 10 mA

Figure 8-13. Buck Output Voltage Ripple, Forced-

PWM Mode

Figure 8-14. Buck Output Voltage Ripple, PFM

Mode

V_OUT= 1.2 V

Figure 8-15. Buck Transient from PFM-to-PWM

Mode

Figure 8-16. Buck Transient from PWM-to-PFM

Mode

I_OUT= 0 A → 3 A → 0 A

T_R= T_F= 1 µs

V_OUT= 1 V

I_OUT= 0 A → 3 A → 0 A

T_R= T_F= 1 µs

V_OUT= 1.2 V

Figure 8-17. Buck Transient Load Step Response, Figure 8-18. Buck Transient Load Step Response,

Forced-PWM Mode Forced-PWM Mode

84

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I_OUT= 0 A → 3 A → 0 A

T_R= T_F= 1 µs

V_OUT= 1 V

V_OUT= 1.2 V

Figure 8-19. Buck Transient Load Step Response,

Auto Mode

Figure 8-20. Buck Transient Load Step Response,

Auto Mode

100

90

80

70

60

50

5.2

5.15

5.1

5.05

5

4.95

4.9

Vout=5.0V, Vin=3.3V

0.4 0.5 0.6

Vout=5.0V, Vin=3.3V

0.1

4.85

40

0.001

0

0.1

0.2 0.3

Output Current (A)

0.01

Output Current (A)

1

D007

D006

.

Figure 8-22. Boost Output Voltage vs Load Current

Figure 8-21. Boost Efficiency

5.04

5.03

5.02

5.01

5

4.99

4.98

4.97

Vout=5.0V, ILoad=0.1A

3.6 3.8

2.8

3

3.2

3.4

Input Voltage (V)

4

D008

I_OUT= 0.1 A

I_OUT= 0 A

Figure 8-23. Boost Output Voltage vs Input Voltage

Figure 8-24. Boost Start-up With EN1, Forced-PWM

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R_LOAD= 50 Ω

Figure 8-26. Boost Shutdown With EN1, Forced-

PWM

Figure 8-25. Boost Start-up With EN1, Forced-PWM

I_OUT= 0 A → 0.25 A → 0 A

T_R= T_F= 1 µs

I_OUT= 0.1 A

Figure 8-28. Boost Transient Load Step Response

Figure 8-27. Boost Output Voltage Ripple

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9 Power Supply Recommendations

The device is designed to operate from an input voltage supply range between 2.8 V and 5.5 V. This input

supply must be well regulated and able to withstand maximum input current and maintain stable voltage without

voltage drop even at load transition condition. The resistance of the input supply rail must be low enough that

the input current transient does not cause too high of a drop in the LP87702 supply voltage that can cause false

UVLO fault triggering. If the input supply is located more than a few inches from the LP87702, additional bulk

capacitance may be required in addition to the ceramic bypass capacitors.

10 Layout

10.1 Layout Guidelines

The high frequency and large switching currents of the LP87702 make the choice of layout important. Good

power supply results only occur when care is given to proper design and layout. Layout affects noise pickup

and generation and can cause a good design to perform with less-than-expected results. With a range of output

currents from milliamps to several amps, good power supply layout is much more difficult than most general PCB

design. Use the following steps as a reference to ensure the device is stable and maintains proper voltage and

current regulation across its intended operating voltage and current range.

1. Place C_INas close as possible to the VIN_Bx pin and the PGND_Bx pin. Route the V_INtrace wide and thick

to avoid IR drops. The trace between the input capacitor's positive node and one or more of the device

VIN_Bx pins, as well as the trace between the negative node of the input capacitor and one or more of the

power PGND_Bx pins must be kept as short as possible. The input capacitance provides a low-impedance

voltage source for the switching converter. The inductance of the connection is the most important parameter

of a local decoupling capacitor – parasitic inductance on these traces must be kept as tiny as possible for

proper device operation.

2. The output filter, consisting of L and C_OUT, converts the switching signal at SW_Bx to the noiseless output

voltage. It should be placed as close as possible to the device keeping the switch node small, for best EMI

behavior. Route the traces between the LP87702 devices output capacitors and the load's input capacitors

direct and wide to avoid losses due to the IR drop.

3. Input for analog blocks (VANA and AGND) should be isolated from noisy signals. Connect VANA directly to a

quiet system voltage node and AGND to a quiet ground point where no IR drop occurs. Place the decoupling

capacitor as close as possible to the VANA pin.

4. If remote voltage sensing can be used for the load, connect the device feedback pins FB_Bx to the

respective sense pins on the load capacitor. The sense lines are susceptible to noise. They must be kept

away from noisy signals such as PGND_Bx, VIN_Bx, and SW_Bx, as well as high bandwidth signals such as

the I²C. Avoid capacitive and inductive coupling by keeping the sense lines short and direct. Run the lines in

a quiet layer. Isolate them from noisy signals by a voltage or ground plane (if possible).

5. PGND_Bx, VIN_Bx and SW_Bx should be routed on thick layers. They must not surround inner signal layers

which are not able to withstand interference from noisy PGND_Bx, VIN_Bx and SW_Bx.

Due to the small package of this converter and the overall small solution size, the thermal performance of the

PCB layout is important. Many system-dependent issues such as thermal coupling, airflow, added heat sinks,

convection surfaces, and the presence of other heat-generating components affect the power dissipation limits

of a given component. Proper PCB layout, focusing on thermal performance, results in lower die temperatures.

Wide power traces come with the ability to sink dissipated heat. This can be improved further on multi-layer

PCB designs with vias to different planes. This results in reduced junction-to-ambient (R_θJA) and junction-to-

board (R_θJB) thermal resistances, which reduces the device junction temperature (T_J). TI strongly recommends

performing a careful system-level 2D or full 3D dynamic thermal analysis at the beginning product design

process, by using a thermal modeling analysis software.

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10.2 Layout Example

VOUT0

VOUT1

C_OUT0

C_OUT1

GND

L1

L0

24 23 22

20

19

21

18 17

16

SW_B0

SW_B1

VIN_B1

25

26

15

14

SW_B0

VIN_B0

C_IN0

C_IN1

27

VIN

28

GND

VIN

13

GND

VIN_B1

GPO0

NRST

12

PG0

29

30

VMON1

11

10

GND

L2

VMON2

31

PGDN_BST

SW_BST

VIN

9

PG1 (GPO1)

32

GND

1

2

3

4

5

6

7

8

GND

C_OUT2

AGND

VIN

C_ANA

Figure 10-1. LP87702 Board Layout Example

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11 Device and Documentation Support

11.1 Third-Party Products Disclaimer

TI'S PUBLICATION OF INFORMATION REGARDING THIRD-PARTY PRODUCTS OR SERVICES DOES NOT

CONSTITUTE AN ENDORSEMENT REGARDING THE SUITABILITY OF SUCH PRODUCTS OR SERVICES

OR A WARRANTY, REPRESENTATION OR ENDORSEMENT OF SUCH PRODUCTS OR SERVICES, EITHER

ALONE OR IN COMBINATION WITH ANY TI PRODUCT OR SERVICE.

11.2 Receiving Notification of Documentation Updates

To receive notification of documentation updates, go to the device product folder on ti.com. In the upper right

corner, click Alert me to register for a weekly digest of any product information that has changed. For change

details, review the revision history included in any revised document.

11.3 Support Resources

TI E2E^™support forums are an engineer's go-to source for fast, verified answers and design help — straight

from the experts. Search existing answers or ask your own question to get the quick design help you need.

Linked content is provided "AS IS" by the respective contributors. They do not constitute TI specifications and do

not necessarily reflect TI's views; see TI's Terms of Use.

11.4 Trademarks

TI E2E^™is a trademark of Texas Instruments.

All trademarks are the property of their respective owners.

11.5 Electrostatic Discharge Caution

This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled

with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.

ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may

be more susceptible to damage because very small parametric changes could cause the device not to meet its published

specifications.

11.6 Glossary

TI Glossary

This glossary lists and explains terms, acronyms, and definitions.

12 Mechanical, Packaging, and Orderable Information

The following pages include mechanical, packaging, and orderable information. This information is the most

current data available for the designated devices. This data is subject to change without notice and revision of

this document. For browser-based versions of this data sheet, refer to the left-hand navigation.

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PACKAGE MATERIALS INFORMATION

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1-Apr-2021

TAPE AND REEL INFORMATION

*All dimensions are nominal

Device

Package Package Pins

Type Drawing

SPQ

Reel

A0

B0

K0

P1

W

Pin1

Diameter Width (mm) (mm) (mm) (mm) (mm) Quadrant

(mm) W1 (mm)

LP87702KRHBR

LP87702KRHBT

VQFN

RHB

32

3000

250

330.0

180.0

12.4

5.25

1.1

8.0

12.0

Q2

Pack Materials-Page 1

PACKAGE MATERIALS INFORMATION

www.ti.com

1-Apr-2021

*All dimensions are nominal

Device

Package Type Package Drawing Pins

SPQ

Length (mm) Width (mm) Height (mm)

LP87702KRHBR

LP87702KRHBT

VQFN

RHB

32

3000

250

367.0

213.0

367.0

191.0

38.0

35.0

Pack Materials-Page 2

GENERIC PACKAGE VIEW

RHB 32

5 x 5, 0.5 mm pitch

VQFN - 1 mm max height

PLASTIC QUAD FLATPACK - NO LEAD

Images above are just a representation of the package family, actual package may vary.

Refer to the product data sheet for package details.

4224745/A

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PACKAGE OUTLINE

RHB0032N

VQFN - 0.9 mm max height

S

C

A

L

E

3

.

0

PLASTIC QUAD FLATPACK - NO LEAD

5.1

4.9

B

A

PIN 1 INDEX AREA

5.1

4.9

0.1 MIN

(0.05)

SECTION A-A

A

TYPICAL

C

0.9 MAX

SEATING PLANE

0.08 C

0.05

0.00

2X 3.5

(0.2) TYP

3.45 0.1

9

EXPOSED

THERMAL PAD

16

28X 0.5

8

17

A

2X

SYMM

33

3.5

0.3

32X

0.2

24

0.1

C A B

1

0.05

C

32

25

PIN 1 ID

(OPTIONAL)

SYMM

0.5

0.3

32X

4222893/B 02/2018

NOTES:

1. All linear dimensions are in millimeters. Any dimensions in parenthesis are for reference only. Dimensioning and tolerancing

per ASME Y14.5M.

2. This drawing is subject to change without notice.

3. The package thermal pad must be soldered to the printed circuit board for thermal and mechanical performance.

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EXAMPLE BOARD LAYOUT

RHB0032N

VQFN - 0.9 mm max height

PLASTIC QUAD FLATPACK - NO LEAD

(

3.45)

SYMM

32

25

32X (0.6)

1

24

32X (0.25)

(1.475)

28X (0.5)

33

SYMM

(4.8)

(

0.2) TYP

VIA

8

17

(R0.05)

TYP

9

16

(1.475)

(4.8)

LAND PATTERN EXAMPLE

EXPOSED METAL SHOWN

SCALE:18X

0.07 MIN

ALL AROUND

0.07 MAX

ALL AROUND

SOLDER MASK

OPENING

METAL EDGE

EXPOSED METAL

EXPOSED

METAL

SOLDER MASK

OPENING

METAL UNDER

SOLDER MASK

NON SOLDER MASK

DEFINED

SOLDER MASK

DEFINED

(PREFERRED)

SOLDER MASK DETAILS

4222893/B 02/2018

NOTES: (continued)

4. This package is designed to be soldered to a thermal pad on the board. For more information, see Texas Instruments literature

number SLUA271 (www.ti.com/lit/slua271).

5. Vias are optional depending on application, refer to device data sheet. If any vias are implemented, refer to their locations shown

on this view. It is recommended that vias under paste be filled, plugged or tented.

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EXAMPLE STENCIL DESIGN

RHB0032N

VQFN - 0.9 mm max height

PLASTIC QUAD FLATPACK - NO LEAD

4X ( 1.49)

(0.845)

(R0.05) TYP

32

25

32X (0.6)

1

24

32X (0.25)

28X (0.5)

(0.845)

SYMM

33

(4.8)

17

8

METAL

TYP

16

9

SYMM

(4.8)

SOLDER PASTE EXAMPLE

BASED ON 0.125 mm THICK STENCIL

EXPOSED PAD 33:

75% PRINTED SOLDER COVERAGE BY AREA UNDER PACKAGE

SCALE:20X

4222893/B 02/2018

NOTES: (continued)

6. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate

design recommendations.

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TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATASHEETS), DESIGN RESOURCES (INCLUDING REFERENCE

DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES “AS IS”

AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY

IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD

PARTY INTELLECTUAL PROPERTY RIGHTS.

These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate

TI products for your application, (2) designing, validating and testing your application, and (3) ensuring your application meets applicable

standards, and any other safety, security, or other requirements. These resources are subject to change without notice. TI grants you

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applicable warranties or warranty disclaimers for TI products.IMPORTANT NOTICE

Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265


型号：	LP87702KRHBR
厂家：	TEXAS INSTRUMENTS
描述：	LP87702 Dual Buck Converter and 5-V Boost With Diagnostic Functions
文件：	总98页 (文件大小：4553K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

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